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Dictionary
| 3-D |
In
computers, 3-D (three dimensions or three-dimensional) describes an
image that provides the perception of depth. When 3-D images are made
interactive so that users feel involved with the scene, the experience
is called virtual reality. You usually need a special plug-in viewer
for your Web browser to view and interact with 3-D images. Virtual
reality experiences may also require additional equipment.
3-D image creation can be viewed as a three-phase process of:
tessellation, geometry, and rendering. In the first phase, models are
created of individual objects using linked points that are made into a
number of individual polygons (tiles). In the next stage, the polygons
are transformed in various ways and lighting effects are applied. In
the third stage, the transformed images are rendered into objects with
very fine detail.
Popular products for creating 3-D effects include Extreme 3D, LightWave
3D, Ray Dream Studio, 3D Studio MAX, Soft Image 3D, and Visual Reality.
The Virtual Reality Modeling Language (VRML) allows the creator to
specify images and the rules for their display and interaction using
textual language statements. |
| |
| ACTIVE X |
ActiveX
is the name Microsoft has given to a set of "strategic" object-oriented
program technologies and tools. The main technology is the Component
Object Model (COM). Used in a network with a directory and additional
support, COM becomes the Distributed Component Object Model (DCOM). The
main thing that you create when writing a program to run in the Active X
environment is a component, a self-sufficient program that can be run
anywhere in your ActiveX network (currently a network consisting of
Windows and Macintosh systems). This component is known as an Active x
control. ActiveX is Microsoft's answer to the Java technology from Sun
Microsystems. An ActiveX control is roughly equivalent to a Java
applet.
If you have a Windows
operating system on your personal computer, you may notice a number of
Windows files with the "OCX" file name suffix. OCX stands for "Object
Linking and Embedding control." Object Linking and Embedding (OLE) was
Microsoft's program technology for supporting compound documents such
as the Windows desktop. The Component Object Model now takes in OLE as
part of a larger concept. Microsoft now uses the term "ActiveX control"
instead of "OCX" for the component object.
One of the main advantages of a component is that it can be re-used by
many applications (referred to as component containers). A COM
component object (Active X control) can be created using one of several
languages or development tools, including C++ and Visual Basic, or
Power Builder, or with scripting tools such as VB Script.
Currently, ActiveX controls run in Windows 95/98/NT and in Macintosh.
Microsoft plans to support ActiveX controls for UNIX. |
| |
| ADDRESS |
The
location of an Internet resource. An email address may take the form of
alias@username.xn----7sbpvgkfboil.xn--j1aef.xn--p1acf A web address looks something like
http://xn----7sbpvgkfboil.xn--j1aef.xn--p1acf |
| |
| ADN |
(Advanced Digital Network) -- Usually refers to a 56Kbps leased-line. |
| |
| ADSL |
ADSL
(Asymmetric Digital Subscriber Line) is a technology for transmitting
digital information at high bandwidths on existing phone lines to homes
and businesses. ADSL is asymmetric in that it uses most of the channel
to transmit downstream to the user and only a small part to receive
information from the user. ADSL simultaneously accommodates analog
(voice) information on the same line. ADSL is generally offered at
downstream data rates from 512 Kbps to about 6 Mbps. A form of ADSL,
known as Universal ADSL or G.Lite, has been initially approved as a
standard by the ITU.
ADSL was
specifically designed to exploit the one-way nature of most multimedia
communication in which large amounts of information flow toward the
user and only a small amount of interactive control information is
returned. Several experiments with ADSL to real users began in 1996. In
1998, wide-scale installations began in several parts of the U.S. ADSL
and other forms of DSL are expected to become more widely available in
1999 and 2000. With ADSL (and other forms of DSL), telephone companies
are competing with cable companies and their cable modem services.
|
| |
| ANCHOR |
Either
the starting point or destination of a hyperlink. The letters at the
top of this page are all anchors - clicking one takes you to another
part of this page. |
| |
| ANONYMOUS FTP |
Using
the Internet's File Transfer Protocol (FTP), anonymous FTP is a method
for giving users access to files so that they don't need to identify
themselves to the server. Using an FTP program or the FTP command
interface, the user enters "anonymous" as a user ID. Usually, the
password is defaulted or furnished by the FTP server. Anonymous FTP is
a common way to get access to a server in order to view or download
files that are publicly available.
If someone tells you to use anonymous FTP and gives you the server
name, just remember to use the word "anonymous" for your user ID.
Usually, you can enter anything as a password. |
| |
| APPLET |
An
applet is a little application program. Prior to the World Wide Web,
the built-in writing and drawing programs that came with Windows were
sometimes called "applets." On the Web, using Java, the object-oriented
programming language, an applet is a small program that can be sent
along with a Web page to a user. Java applets can perform interactive
animations, immediate calculations, or other simple tasks without
having to send a user request back to the server. |
| |
| ARCHIVE |
1)
An archive is a collection of computer files that have been packaged
together for backup, to transport to some other location, for saving
away from the computer so that more hard disk storage can be made
available, or for some other purpose. An archive can include a simple
list of files or files organized under a directory or catalog structure
(depending on how a particular program supports archiving).
On personal computers with the Windows operating system, WinZip is a
popular program that lets you create an archive (a single file that
holds a number of files that you plan to save to another medium or send
someone electronically) or extract the files. WinZip also compresses
the files that are archived, but compression is not required to create
an archive. A Win Zip archive has the file name suffix ".zip".
In UNIX-based operating systems, the tar (tape archive) utility can be
used to create an archive or extract files from one. On mainframe
operating systems such as IBMs MVS and OS/390, procedures for archiving
or backing up files are often automated as a daily operation.
2) On Web sites as well as in libraries, an archive is a collection of
individual publications that are often cataloged or listed and made
accessible in some way. Magazines, journals, and newspapers with Web
sites sometimes refer to their back issues as an archive.
3) Web and FTP sites that provide software programs that can be
downloaded sometimes refer to the list of downloadable files as an
archive or as archives. |
| |
| ARJ |
Allows
the user to store one or more files in a compressed format in an
archive file. This saves space both in the compression and in the
saving of disk sector clusters. Particularly strong compressing
databases, uncompressed graphics files, and large documents. Named
after the creator, American programmer Robert Jung. |
| |
| ARPANET |
(Advanced
Research Projects Agency Network) -- The precursor to the Internet.
Developed in the late 60's and early 70's by the US Department of
Defense as an experiment in wide-area-networking that would survive a
nuclear war. |
| |
| ASCII |
ASCII
is the most common format for text files in computers and on the
"Internet". In an ASCII file, each alphabetic, numeric, or special
character is represented with a 7-bit binary number (a string of seven
0s or 1s). 128 possible characters are defined.
UNIX and DOS-based operating systems (except for Windows NT) use ASCII
for text files. Windows NT uses a newer code, Unicode. IBMs System 390
servers use a proprietary 8-bit code called EBCDIC. Conversion programs
allow different operating systems to change a file from one code to
another.
ASCII was developed by the American National Standards Institute (ANSI). |
| |
| ASP |
An
Active Server Page (ASP) is an HTML page that includes one or more
scripts (small embedded programs) that are processed on a Microsoft Web
server before the page is sent to the user. An ASP is somewhat similar
to a server-side include or a common gateway interface (CGI)
application in that all involve programs that run on the server,
usually tailoring a page for the user. Typically, the script in the Web
page at the server uses input received as the result of the user's
request for the page to access data from a database and then builds or
customizes the page on the fly before sending it to the requestor.
ASP is a feature of the Microsoft Internet Information Server (IIS),
but, since the server-side script is just building a regular HTML page,
it can be delivered to almost any browser. You can create an ASP file
by including a script written in VBScript or JScript in an HTML file or
by using ActiveX Data Objects (ADO) program statements in the HTML
file. You name the HTML file with the ".asp" file suffix. Microsoft
recommends the use of the server-side ASP rather than a client-side
script, where there is actually a choice, because the server-side
script will result in an easily displayable HTML page. Client-side
scripts (for example, with JavaScript) may not work as intended on
older browsers. |
| |
| ASPI |
Advanced Scsi Programming Interface. |
| |
| ATX |
ATX
is an industry-wide open specification for a desktop computer's
motherboard. The most current version (December, 1996) is Specification
2.0.
ATX improves the
motherboard design by taking the small AT motherboard that has been an
industry standard and rotating by 90 degrees the layout of the
microprocessor and expansion slots. This allows space for more
full-length add-in cards. A double-height aperture is specified for the
rear of the chassis, allowing more possible I/O arrangements for a
variety of devices such as TV input and output, LAN connection, and so
forth. The new layout is also intended to be less costly to
manufacture. Fewer cables will be needed. The power supply has a
side-mounted fan, allowing direct cooling of the processor and cards,
making a secondary fan unnecessary. Version 2.0 incorporates
improvements suggested by chassis and power supply vendors.
Almost all major computer manufacturers, including IBM, Compaq, and
Apple are building desktops with ATX motherboards. IBM is using ATX in
both Intel and Power PC platforms. |
| |
| AUTHENTICATION |
A
security measure for checking a user's identity (user ID). Some Web
sites require a user's identity to be authenticated before they can
enter. This is usually done with a password and or username. |
| |
| AUTO
RESPONDER |
An
auto responder is a computer program that automatically returns a
prewritten message to anyone who submits email to a particular Internet
address, whether an individual or a Web site. Autoresponders are widely
used by Web sites for the purpose of responding to visitor comments and
suggestions in a preliminary way and, in cases where traffic is heavy,
as the sole way to communicate with user inquiries.
Publishers of ezines and other online email newsletters typically use
an autoresponder to respond to people who subscribe or cancel their
subscriptions. |
| |
| BACKBONE |
A backbone is a larger transmission line that carries data gathered from smaller lines that interconnect with it.
1) At the local level, a backbone is a line or set of lines that local
area networks connect to for a wide area network connection or within a
local area network to span distances efficiently (for example, between
buildings).
2) On the Internet or other wide area network, a backbone is a set of
paths that local or regional networks connect to for long-distance
interconnection. The connection points are known as network nodes or
telecommunication data switching exchanges (DSEs).
|
| |
| BANDWIDTH |
The
bandwidth of a transmitted communications signal is a measure of the
range of frequencies the signal occupies. The term is also used in
reference to the frequency-response characteristics of a communications
receiving system. All transmitted signals, whether analog or digital,
have a certain bandwidth. The same is true of receiving systems.
Generally speaking, bandwidth is directly proportional to the amount of
data transmitted or received per unit time. In a qualitative sense,
bandwidth is proportional to the complexity of the data for a given
level of system performance. For example, it takes more bandwidth to
download a photograph in one second than it takes to download a page of
text in one second. Large sound files, computer programs, and animated
videos require still more bandwidth for acceptable system performance.
Virtual reality (VR) and full-length three-dimensional audio/visual
presentations require the most bandwidth of all.
In digital systems, bandwidth is data speed in bits per second (bps).
Thus, a modem that works at 57,600 bps has twice the bandwidth of a
modem that works at 28,800 bps. In analog systems, bandwidth is defined
in terms of the difference between the highest-frequency signal
component and the lowest-frequency signal component. Frequency is
measured in cycles per second (hertz). A typical voice signal has a
bandwidth of approximately three kilohertz (3 kHz); an analog
television (TV) broadcast video signal has a bandwidth of six megahertz
(6 MHz) -- some 2,000 times as wide as the voice signal. |
| |
| BAUD |
Baud
was the prevalent measure for data transmission speed until replaced by
a more accurate term, bps (bits per second). One baud is one electronic
state change per second. Since a single state change can involve more
than a single bit of data, the bps unit of measurement has replaced it
as a better expression of data transmission speed.
The measure was named after a French engineer, Jean-Maurice-Emile
Baudot. It was first used to measure the speed of telegraph
transmissions. |
| |
| BBS |
A
BBS (bulletin board system) is a computer that can be reached by
computer modem dialling (and, in some cases, by Telnet) for the purpose
of sharing or exchanging messages or other files. Some BBSs are devoted
to specific interests; others offer a more general service. The
definitive BBS List says that there are 40,000 BBSs world-wide.
Among special interests represented on BBSs are dentistry, law, guns,
multi-player games, Druidic practices, and information for the
disabled. A significant number of BBS sites offer "adult-oriented" chat
and images that can be downloaded. Many BBSs are free; some charge a
membership or use fee.
Essentially, a bulletin board system is a host computer that is
accessible by dial-up phone (you need to know the phone number) or, at
some sites, via Telnet. Since calling a bulletin board system can
involve long-distance charges, you may want to try starting with some
in your area.
Bulletin board systems originated and generally operate independently
of the Internet. However, many BBSs have Web sites. And many Internet
access providers have bulletin board systems from which new Internet
users can download the necessary software to get connected.
BBSs have their own culture and jargon. A sysop is the person who runs
the site (many BBSs are on small home computers that have simply added
the necessary software to keep track of files and users). |
| |
| BINHEX |
BinHex
is a utility for converting (encoding) Macintosh files into files that
will travel well on networks either as files or email attachments. Like
Uuencode, BinHex encodes a file from 8-bit binary or bit-stream
representation into a 7-bit ASCII set of text characters. The recipient
must decode it at the other end. Older email utilities sometimes cant
handle binary transmissions so text encoding ensures that a
transmission will get to an older system. BinHex specifically handles
both resource and data forks in Macintosh files (which Uuencode
doesnt). BinHex files have a suffix of ".hqx". (Earlier versions have
the suffix ".hex".)
Netscape
and possibly other Web browsers as well as some popular email
applications (including Eudora) include BinHex encoding and decoding
capability. Otherwise, you can download a BinHex utility for use in
either the Macintosh, Windows, or other systems. (In Eudora, when
writing a note you want to be transmitted in BinHex, look for the
little box set to a default of "MIME" and change it to "BinHex".) |
| |
| BIOS |
BIOS
(basic input/output system) is the program a personal computers
microprocessor uses to get the computer system started after you turn
it on. It also manages data flow between the computers operating system
and attached devices such as the hard disk, video adapter, keyboard,
mouse, and printer.
BIOS is an
integral part of your computer and comes with it when you bring it
home. (In contrast, the operating system can either be preinstalled by
the manufacturer or vendor or installed by the user.) BIOS is a program
that is made accessible to the microprocessor on an erasable
programmable read-only memory (EPROM) chip. When you turn on your
computer, the microprocessor passes control to the BIOS program, which
is always located at the same place on EPROM.
When BIOS boots up (starts up) your computer, it first determines
whether all of the attachments are in place and operational and then it
loads the operating system (or key parts of it) into your computers
random access memory RAM from your hard disk or diskette drive.
With BIOS, your operating system and applications are freed from having
to understand exact details (such as hardware addresses) about the
attached input/output devices. When device details change, only the
BIOS program needs to be changed. Sometimes this change can be made
during your system setup. In any case, neither your operating system or
any applications you use need to be changed.
Although BIOS is theoretically always the intermediary between the
microprocessor and I/O device control information and data flow, in
some cases, BIOS can arrange for data to flow directly to memory from
devices (such as video cards) that require faster data flow to be
effective.
|
| |
| BIT |
A
bit is the smallest unit of data in a computer. A bit has a single
binary value, either 0 or 1. Although computers usually provide
instructions that can test and manipulate bits, they generally are
designed to store data and execute instructions in bit multiples called
bytes. In most computer systems, there are eight bits in a byte. The
value of a bit is usually stored as either above or below a designated
level of electrical charge in a single capacitor within a memory
device.
Half a byte (four bits)
is called a nibble. In some systems, the term octet is used for an
eight-bit unit instead of byte. In many systems, four eight-bit bytes
or octets form a 32-bit word. In such systems, instruction lengths are
sometimes expressed as full-word (32 bits in length) or half-word (16
bits in length).
In telecommunication, the bit rate is the number of bits that are transmitted in a given time period, usually a second.
|
| |
| BLUE SCREEN (of death) |
The
blue screen of death is a rather terrifying display image containing
white text on a blue background that is generated by Windows operating
systems when the system has suddenly terminated with an error. The
system is locked up and must be restarted. The blue screen may include
some hexadecimal values from a memory dump that may help determine what
caused the crash.
The blue
screen of death can strike anywhere. At the Comdex trade show,
Microsoft Chairman Bill Gates encountered the blue screen during a
demonstration of Windows 98. (He had a spare computer standing by.) |
| |
| BODY |
In email terms, the part of the message containing the most textual content, sandwiched between the Header and the Signature. |
| |
| BOOKMARK |
Using
a World Wide Web browser, a bookmark is a saved link to a Web page that
has been added to a list of saved links. When you are looking at a
particular Web site or home page and want to be able to quickly get
back to it later, you can create a bookmark for it. You can think of
your browser as a book full of (millions of ) Web pages and a few
well-placed bookmarks that you have chosen. The list that contains your
bookmarks is the "bookmark list" (and sometimes it is called a
"hotlist").
Netscape and some other browsers use the bookmark idea. Microsofts Internet Explorer uses the term "favourite." |
| |
| BOT |
A
bot (short for "robot") is a program that operates as an agent for a
user or another program or simulates a human activity. On the Internet,
the most ubiquitous bots are the programs, also called spiders or
crawlers, that access Web sites and gather their content for search
engine indexes.
A chatterbot is
a program that can simulate talk with a human being. One of the first
and most famous chatterbots (prior to the Web) was Eliza, a program
that pretended to be a psychotherapist and answered questions with
other questions.
Red and Andrette are two examples of programs that can be customized to
answer questions from users seeking service for a product. Such a
program is sometimes called a virtual representative or a virtual
service agent.
Shopbots are programs that shop around the Web on your behalf and
locate the best price for a product you're looking for. There are also
bots such as OpenSesame that observe a user's patterns in navigating a
Web site and customize the site for that user. |
| |
| BPS |
In
data communications, bits per second (abbreviated bps) is a common
measure of data speed for computer modems and transmission carriers. As
the term implies, the speed in bps is equal to the number of bits
transmitted or received each second. The duration d of a data bit, in
seconds, is inversely proportional to the digital transmission speed s
in bps:
d = 1/s
Larger units are sometimes used to denote high data speeds. One kilobit
per second (abbreviated Kbps in the U.S.; kbps elsewhere) is equal to
1,000 bps. One megabit per second (Mbps) is equal to 1,000,000 bps or
1,000 kbps.
Computer modems for twisted-pair telephone lines usually operate at
speeds between 14.4 and 57.6 kbps. The most common speeds are 28.8 and
33.6 kbps. So-called "cable modems," designed for use with TV cable
networks, can operate at more than 100 kbps. Fibreoptic modems are the
fastest of all; they can send and receive data at many Mbps.
The bandwidth of a signal depends on the speed in bps. With some
exceptions, the higher the bps number, the greater is the nominal
signal bandwidth. (Speed and bandwidth are, however, not the same
thing.) Bandwidth is measured in standard frequency units of kilohertz
(kHz) or megahertz (MHz).
Data speed is sometimes specified in terms of baud, which is a measure
of the number of times a digital signal changes state in one second.
Baud, sometimes called the "baud rate," is almost always a lower figure
than bps for a given digital signal. The terms are often used
interchangeably, even though they do not refer to the same thing. If
you hear that a computer modem can function at "33,600 baud" or "33.6
kilobaud," you can be reasonably sure that the term is being misused,
and the figures actually indicate bps.
|
| |
| BRB |
Abbreviations of Be Right Back, commonly used online or on IRC. |
| |
| BROWSER |
A
browser is an application program that provides a way to look at and
interact with all the information on the World Wide Web. The word
"browser" seems to have originated prior to the Web as a generic term
for user interfaces that let you browse text files online. By the time
the first Web browser with a graphical user interface was invented
(Mosaic, in 1992), the term seemed to apply to Web content, too.
Technically, a Web browser is a client program that uses the Hypertext
Transfer Protocol (HTTP) to make requests of Web servers throughout the
Internet on behalf of the browser user. A commercial version of the
original browser, Mosaic, is in use. Many of the user interface
features in Mosaic, however, went into the first widely-used browser,
Netscape Navigator. Microsoft followed with Internet Explorer. Today,
these two browsers are highly competitive and the only two browsers
that the vast majority of Internet users are aware of. Although the
online services, such as America Online, Compuserve, and Prodigy,
originally had their own browsers, virtually all now offer the Netscape
or Microsoft browser. Lynx is a text-only browser for UNIX shell and
VMS users. Another recently offered browser is Opera. |
| |
| BTW |
Meaning by the way, a shorthand form to a comment written in an online forum, such as the newsgroups or IRC (chat) |
| |
| BYTE |
In
most computer systems, a byte is a unit of information that is eight
bits long. A byte is the unit most computers use to represent a
character such as a letter, number, or typographic symbol (for example,
"g", "5", or "?"). A byte can also hold a string of bits that need to
be used in some larger unit for application purposes (for example, the
stream of bits that constitute a visual image for a program that
displays images).
In some
computer systems, four bytes constitute a word, a unit that a computer
processor can be designed to handle efficiently as it reads and
processes each instruction. Some computer processors can handle
two-byte or single-byte instructions.
A byte is abbreviated with a "B". (A bit is abbreviated with a small
"b".) Computer storage is usually measured in byte multiples. For
example, an 820 MB hard drive holds a nominal 820 million bytes - or
megabytes - of information. Byte multiples are based on powers of 2 and
commonly expressed as a "rounded off" decimal number. For example, one
megabyte ("one million bytes") is actually 1,048,576 (decimal) bytes.
(Confusingly, however, some hard disk manufacturers and dictionary
sources state that bytes for computer storage should be calculated as
powers of 10 so that a megabyte really would be one million decimal
bytes.)
Some language scripts require two bytes to represent a character. These are called double-byte character sets (DBCS).
According to Fred Brooks, an early hardware architect for IBM, project
manager for the OS/360 operating system, and author of The Mythical
Man-Month, Dr. Werner Buchholz originated the term byte in 1956 when
working on IBM's STRETCH computer.
|
| |
| CABLE MODEM |
A
cable modem is a device that enables you to hook up your PC to a local
cable TV line and receive data at about 1.5 Mbps. This data rate far
exceeds that of the prevalent 28.8 and 56 Kbps telephone modems and the
up to 128 Kbps of ISDN and is about the data rate available to
subscribers of Digital Subscriber Line (DSL) telephone service. A cable
modem can be added to or integrated with a set-top box that provides
your TV set with channels for Internet access. In most cases, cable
modems are furnished as part of the cable access service and are not
purchased directly and installed by the subscriber.
A cable modem has two connections: one to the cable wall outlet and the
other to a PC or to a set-top box for a TV set. Although a cable modem
does modulate between analog and digital signals, it is a much more
complex device than a telephone modem. It can be an external device or
it can be integrated within a computer or set-top box. Typically, the
cable modem attaches to a standard 10Base-T Ethernet card in the
computer.
All of the cable modems attached to a cable TV company coaxial cable
line communicate with a Cable Modem Termination System (CMTS) at the
local cable TV company office. All cable modems can receive from and
send signals only to the CMTS, but not to other cable modems on the
line. Some services have the upstream signals returned by telephone
rather than cable, in which case the cable modem is known as a
telco-return cable modem.
The actual bandwidth for Internet service over a cable TV line is up to
27 Mbps on the download path to the subscriber with about 2.5 Mbps of
bandwidth for interactive responses in the other direction. However,
since the local provider may not be connected to the Internet on a line
faster than a T-1 at 1.5 Mpbs, a more likely data rate will be close to
1.5 Mpbs. |
| |
| CGI |
The
common gateway interface (CGI) is a standard way for a Web server to
pass a Web user's request to an application program and to receive data
back to forward to the user. When the user requests a Web page (for
example, by clicking on a highlighted word or entering a Web site
address), the server sends back the requested page. However, when a
user fills out a form on a Web page and sends it in, it usually needs
to be processed by an application program. The Web server typically
passes the form information to a small application program that
processes the data and may send back a confirmation message. This
method or convention for passing data back and forth between the server
and the application is called the common gateway interface (CGI). It is
part of the Web's HTTP protocol.
If you are creating a Web site and want a CGI application to get
control, you specify the name of the application in the URL that you
code in an HTML file. This URL can be specified as part of the FORMS
tags if you are creating a form. For example, you might code:
<FORM METHOD=POST ACTION=http://www.mybiz.com/cgi-bin/formprog.pl>
and the server at "mybiz.com" would pass control to the CGI application
called "formprog.pl" to record the entered data and return a
confirmation message. (The ".pl" indicates a program written in Perl
but other languages could have been used.)
The common gateway interface provides a consistent way for data to be
passed from the user's request to the application program and back to
the user. This means that the person who writes the application program
can makes sure it gets used no matter which operating system the server
uses (PC, Macintosh, UNIX, OS/390, or others). It's simply a basic way
for information to be passed from the Web server about your request to
the application program and back again. |
| |
| CGI-BIN |
The most common name of a directory on a web server in which CGI programs are stored.
The “bin” part of “cgi-bin” is a shorthand version of “binary”, because
once upon a time, most programs were referred to as “binaries”. In real
life, most programs found in cgi-bin directories are text files --
scripts that are executed by binaries located elsewhere on the same
machine. |
| |
| CHAP |
CHAP
(Challenge-Handshake Authentication Protocol) is a more secure
procedure for connecting to a system than the Password Authentication
Procedure (PAP). Heres how CHAP works:
1.After the link is made, the server sends a challenge message to the
connection requestor. The requestor responds with a value obtained by
using a one-way hash function.
2.The server checks the response by comparing calculation of the expected hash value.
3.If the values match, the authentication is acknowledged; otherwise the connection is usually terminated.
At any time, the server can request the connected party to send a new
challenge message. Because CHAP identifiers are changed frequently and
because authentication can be requested by the server at any time, CHAP
provides more security than PAP. RFC1334 defines both CHAP and PAP. |
| |
| CHAT/IRC/ACRONYMNS |
ADN Any day now
AFAIK As far as I know
AFK Away from keyboard
ARE Acronym-rich environment
A/S/L? Age/sex/location?
B4N Bye for now
BAK Back at the keyboard
BBIAB Be back in a bit
BBL Be back later
BEG Big evil grin
BFN Bye for now
BG Big grin
BIOYIOP Blow it out your I/O port
BL Belly laughing
BOTEC Back-of-the-envelope calculation
BRB Be right back
BTA But then again...
BTW By the way
BWTHDIK But what the heck do I know...?
CU See you
CUL See you later
CUL8ER See you later
CYA Cover your ass
CYO See you online
DBA Doing business as
DFLA Disenhanced four-letter acronym (that is, a TLA)
DIKU Do I know you?
DITYID Did I tell you I'm distressed?
DQMOT Don't quote me on this
EG Evil grin
EMFBI Excuse me for butting in
EOM End of message
EOT End of thread (meaning: end of discussion)
ETLA Extended three-letter acronym (that is, an FLA)
F2F Face to face
FAQ Frequently-ask question(s)
FISH First in, still here
FLA Four-letter acronym
FMTYEWTK Far more than you ever wanted to know
FOMCL Falling off my chair laughing
FUD Fear, Uncertainty, and Doubt
FWIW For what it's worth
FYI For your information
G Grin
GA Go ahead
GAL Get a life
GD&R Grinning, ducking, and running
GIWIST Gee, I wish I'd said that
GMTA Great minds think alike
GOL Giggling out loud
GTRM Going to read mail
HAND Have a nice day
HTH Hope this helps
IAC In any case
IANAL I am not a lawyer (but)
IC I see
IHA I hate acronyms
IIRC If I recall/remember/recollect correctly
ILU or ILY I love you
IM Immediate message
IMHO In my humble opinion
IMing Chatting with someone online usually while doing other things such as playing trivia or other interactive game
IMNSHO In my not so humble opinion
IMO In my opinion
IOW In other words
IPN I'm posting naked
IRL In real life (that is, when not chatting)
IYSWIM If you see what I mean
JBOD Just a bunch of disks (like RAID, etc.)
JIC Just in case
JK Just kidding
KOTC Kiss on the cheek
KWIM? Know what I mean?
L8R Later
LD Later, dude
LDR Long-distance relationship
LLTA Lots and lots of thunderous applause
LOL Laughing out loud
LRF Little Rubber Feet (the little pads on the bottom of displays and other equipment)
LTM Laugh to myself
LTNS Long time no see
LTR Long-term relationship
LULAB Love you like a brother
LULAS Love you like a sister
MorF Male or female
MOSS Member of the same sex
MOTOS Member of the opposite sex
MUSM Miss you so much
NIFOC Naked in front of computer
NP or N/P No problem
NRN No response necessary
OIC Oh, I see
OLL Online love
OTF Off the floor
OTOH On the other hand
OTTOMH Off the top of my head
PANS Pretty awesome new stuff (as opposed to "POTS")
PCMCIA People can't master computer industry acronyms
PDA Public display of affection
PEBCAK Problem exists between chair and keyboard
PIBKAC Problem is between keyboard and chair
PITA Pain in the ass
PMFJIB Pardon me for jumping in but...
::POOF:: Goodbye (leaving the room)
POTS Plain old telephone service
PU That stinks!
RL Real life (that is, when not chatting)
ROR Raffing out roud (Engrish for "laughing out loud")
ROTFL (or ROFL) Rolling on the floor laughing
ROTFLMAO Rolling on the floor laughing my a** off
ROTFLMAOWPIMP Rolling on the floor laughing my a** off while peeing in my pants
ROTFLMBO Rolling on the floor laughing my butt off
RPG Role-playing games
RSN Real soon now
RYO Roll your own (write your own program; derived from cigarettes rolled yourself with tobacco and paper)
S4L Spam for life (what you may get when you become someone's customer or client)
SF Surfer-friendly (low-graphics Web site)
SO Significant other
SOMY Sick of me yet?
STW Search the Web
TAFN That's all for now
TANSTAAFL There ain't no such thing as a free lunch
TFH Thread from hell (a discussion that just won't die and is often irrelevant to the purpose of the forum or group)
TGIF Thank God it's Friday
THX Thanks
TIA Thanks in advance (used if you post a question and are expecting a helpful reply)
TLA Three-letter acronym
TLK2UL8R Talk to you later
TMI Too much information
TOPCA Til our paths cross again (early Celtic chat term)
TPTB The powers that be
TTFN Ta-Ta for now
TTT Thought that, too (when someone types in what you were about to type)
TTYL Talk to you later
TU Thank you
UW You're welcome
VBG Very big grin
WDALYIC Who died and left you in charge?
WFM Works for me
WIBNI Wouldn't it be nice if
WT? What/who the ?
WTG Way to go!
WTGP? Want to go private?
WU? What's up?
WUF? Where are you from?
WYSIWYG What you see is what you get
YMMV Your mileage may vary. |
| |
| CLI |
Caller
Line Identification this is the number that you are ringing from, if
you are making a call to the Internet, many free internet service
providers will need you to produce your CLI (show the number you are
ringing from). If your number is witheld you will not be able to
connect. Try adding 1470 before the number you are dialling to
unwithold your CLI. |
| |
| CLIENT |
A
client is the requesting program or user in a client/server
relationship. For example, the user of a Web browser is effectively
making client requests for pages from servers all over the Web. The
browser itself is a client in relationship with the computer that is
getting and returning the requested HTML file. The computer handling
the request and sending back the HTML file is a server. |
| |
| CLIENT SERVER PROTOCOL |
A
communication protocol between networked computers in which the
services of one computer (the server) are requested by the other (the
client). |
| |
| COLOCATION |
Colocation
(sometimes spelled "co-location" or "collocation") is the provision of
space for a customers telecommunications equipment on the service
providers premises. For example, a Web site owner could place the sites
own computer server on the premises of the Internet service provider
(ISP). Or an ISP could place their network router on the premises of
the company offering switching services with other ISPs. The
alternative to colocation is to have the equipment and the demarcation
point located at the customers premises. |
| |
| COMPRESSED |
Data
files available for download from the Internet are typically compacted
in order to save server space and reduce transfer times. Typical file
extensions for compressed files include zip (DOS/Windows) and tar
(UNIX). |
| |
| COOKIE |
The
most common meaning of “Cookie” on the Internet refers to a piece of
information sent by a Web Server to a Web Browser that the Browser
software is expected to save and to send back to the Server whenever
the browser makes additional requests from the Server.
Depending on the type of Cookie used, and the Browser's settings, the
Browser may accept or not accept the Cookie, and may save the Cookie
for either a short time or a long time.
Cookies might contain information such as login or registration
information, online “shopping cart” information, user preferences, etc.
When a Server receives a request from a Browser that includes a Cookie,
the Server is able to use the information stored in the Cookie. For
example, the Server might customize what is sent back to the user, or
keep a log of particular user's requests.
Cookies are usually set to expire after a predetermined amount of time
and are usually saved in memory until the Browser software is closed
down, at which time they may be saved to disk if their “expire time”
has not been reached.
Cookies do not read your hard drive and send your life story to the
FBI, but they can be used to gather more information about a user than
would be possible without them. |
| |
| CSS |
A
cascading style sheet (CSS) is a Web page style sheet derived from
multiple sources with a defined order of precedence where the
definitions of any style element conflict. The Cascading Style Sheet,
level 1 (CSS1) recommendation from the World Wide Web Consortium (W3C),
which is implemented in the latest versions of the Netscape and
Microsoft Web browsers, specifies the possible style sheets or
statements that may determine how a given element is presented in a Web
page.
CSS gives more control
over the appearance of a Web page to the page creator than to the
browser designer or the viewer. With CSS, the sources of style
definition for a given document element are in this order of
precedence:
The STYLE attribute on an individual element tag
The STYLE element that defines a specific style sheet containing style
declarations or a LINK element that links to a separate document
containing the STYLE element. In a Web page, the STYLE element is
placed between the TITLE statement and the BODY statement.
An imported style sheet, using the CSS @import notation to
automatically import and merge an external style sheet with the current
style sheet
Style attributes specified by the viewer to the browser
The default style sheet assumed by the browser
In general, the Web page creator's style sheet takes precedence, but
it's recommended that browsers provide ways for the viewer to override
the style attributes in some respects. Since it's likely that different
browsers will choose to implement CSS1 somewhat differently, the Web
page creator must test the page with different browsers. |
| |
| CU |
Abbreviation of see you, commonly used online or on IRC. |
| |
| CYBERPUNK |
Cyberpunk
is a sensibility or belief that a few outsiders, armed with their own
individuality and technological capability, can fend off the tendencies
of traditional institutions to use technology to control society. The
term, combining "cyber" and punk, possibly originated in 1980 with
Bruce Bethkes short story, "Cyberpunk." An editor of Isaac Asimovs
Science Fiction Magazine, Gardner Dozois, is credited with associating
the word with a literary movement that includes the science fiction of
William Gibson and Neal Stephenson.
The alt.cyberpunk. FAQ lists several categories of groups associated with cyberpunk:
Hackers, who represent the best kind of cyberpunk
Crackers, who attempt to break into computer systems
Phreaks, who attempt to break into telephone systems
Cypher-punks, who attempt to break codes and foil security systems
Additional groups include "transhumans," who attempt to exploit
technology to increase life expectancy and human potential and
"extropians," a kind of libertarian group that believes in something
called "spontaneous order." The writer of the alt.cyberpunk.
FAQ indicates that some people believe cyberpunk to be (intrinsically)
indefinable and that anyone claiming to be a "cyberpunk" will likely be
laughed off their Usenet newsgroup. |
| |
| CYBERSPACE |
Term
originated by author William Gibson in his novel Neuromancer the word
Cyberspace is currently used to describe the whole range of information
resources available through computer networks, most commonly used to
describe the Net |
| |
| DAEMON |
A
daemon (pronounced DEE-muhn) is a program that runs continuously and
exists for the purpose of handling periodic service requests that a
computer system expects to receive. The daemon program forwards the
requests to other programs (or processes) as appropriate. Each server
of pages on the Web has an HTTPD or Hypertext Transfer Protocol daemon
that continually waits for requests to come in from Web clients and
their users.
In mythology, a daemon, according to Webster's, was "an attendant power or spirit."
Daemon can be confused with demon, which has a different but similar
meaning. The New Hackers Dictionary says that a daemon is a program
that runs by itself directly under the operating system whereas a demon
is part of a larger application program.
|
| |
| DAT |
DAT
(Digital Audio Tape) is a standard medium and technology for the
digital recording of audio on tape at a professional level of quality.
A DAT drive is a digital tape recorder with rotating heads similar to
those found in a video deck. Most DAT drives can record at sample rates
of 44.1 KHz, the CD audio standard, and 48 KHz. DAT has become the
standard archiving technology in professional and semi-professional
recording environments for master recordings. Digital inputs and
outputs on professional DAT decks allow the user to transfer recordings
from the DAT tape to an audio workstation for precise editing. The
compact size and low cost of the DAT medium makes it an excellent way
to compile the recordings that are going to be used to create a CD
master.
As an archival medium, DAT is an alternative to consider along with:
Digital Data Storage (DDS1 through DDS3)
Optical disk
VHS tape |
| |
| DHCP |
DHCP
(Dynamic Host Configuration Protocol) is a protocol that lets network
administrators manage centrally and automate the assignment of Internet
Protocol (IP) addresses in an organisations network. Using the
Internets set of protocols (TCP/IP), each machine that can connect to
the Internet needs a unique IP address. When an organisation sets up
its computer users with a connection to the Internet, an IP address
must be assigned to each machine.
Without DHCP, the IP address must be entered manually at each computer
and, if computers move to another location in another part of the
network, a new IP address must be entered. DHCP lets a network
administrator supervise and distribute IP addresses from a central
point and automatically sends a new IP address when a computer is
plugged into a different place in the network.
DHCP uses the concept of a "lease" or amount of time that a given IP
address will be valid for a computer. The lease time can vary depending
on how long a user is likely to require the Internet connection at a
particular location. It is especially useful in education and other
environments where users change frequently. Using very short leases,
DHCP can dynamically reconfigure networks in which there are more
computers than there are available IP addresses.
DHCP supports static addresses for computers containing Web servers that need a permanent IP address.
DHCP is an alternative to another network IP management protocol, BOOTP
(Bootstrap Protocol). DHCP is a more advanced protocol, but both
configuration management protocols are commonly used. Some
organisations use both protocols, but understanding how and when to use
them in the same organisation is important. Some operating systems,
including Windows NT, come with DHCP servers. A DHCP or BOOTP client is
a program that is located in (and perhaps downloaded to) each computer
so that it can be configured. |
| |
| DIAL UP CONNECTION |
A connection to the Internet via phone and modem. Connection types include PPP and SLIP. |
| |
| DIALUP |
'Dialup Access' or a 'Dialup Account' is when a modem is used to gain access to the Internet via a network. |
| |
| DIGERATI |
The
digital version of literati, it is a reference to a vague cloud of
people seen to be knowledgeable, hip, or otherwise in-the-know in
regards to the digital revolution. |
| |
| DIRECT CONNECTION |
A connection made directly to the Internet - much faster than a dial-up connection. |
| |
| DIRECTORY |
A directory is, in general, an approach to organizing information, the most familiar example being a telephone directory.
1) On the World Wide Web, a directory is a subject guide, typically
organized by major topics and subtopics. The best-known directory is
the one at Yahoo (http://www.yahoo.com). Many other sites now use a
Yahoo-like directory including major portal sites.
2) In computer file systems, a directory is a named group of related
files that are separated by the naming convention from other groups of
files.
I.E: C:\
OR C:\WINDOWS\ |
| |
| DISCUSSION GROUP |
A
particular section within the USENET system typically, though not
always, dedicated to a particular subject of interest. Also known as a
newsgroup. |
| |
| DLL |
In
computers, a dynamic link library (DLL) is a collection of small
programs, any of which can be called when needed by a larger program
that is running in the computer. The small program that lets the larger
program communicate with a specific device such as a printer or scanner
is often packaged as a DLL program (usually referred to as a DLL file).
The advantage of DLL files is
that, because they don't get loaded into random access memory (RAM)
together with the main program, space is saved in RAM. When and if a
DLL file is needed, then it is loaded and run. For example, as long as
a user of Microsoft Word is editing a document, the printer DLL file
does not need to be loaded into RAM. If the user decides to print the
document, then the Word application causes the printer DLL file to be
loaded and run.
A DLL file is often given a ".dll" file name suffix. DLL files are
dynamically linked with the program that uses them during program
execution rather than being compiled with the main program. The set of
such files (or the DLL) is somewhat comparable to the library routines
provided with programming languages such as C and C++. |
| |
| DNS |
The
domain name system (DNS) is the way that Internet domain names are
located and translated into IP (Internet Protocol) addresses. A domain
name is a meaningful and easy-to-remember "handle" for an Internet
address.
Because maintaining a
central list of domain name/IP address correspondences would be
impractical, the lists of domain names and IP addresses are distributed
throughout the Internet in a hierarchy of authority. There is probably
a DNS server within close geographic proximity to your access provider
that maps the domain names in your Internet requests or forwards them
to other servers in the Internet. |
| |
| DOMAIN NAME |
The
unique name that identifies an Internet site. Domain Names always have
2 or more parts, separated by dots. The part on the left is the most
specific, and the part on the right is the most general. A given
machine may have more than one Domain Name but a given Domain Name
points to only one machine. For example, the domain names:
breathepro.com
mail.breathepro.com
relay.breathepro.com
can all refer to the same machine, but each domain name can refer to no more than one machine.
Usually, all of the machines on a given Network will have the same
thing as the right-hand portion of their Domain Names (breathepro.com
in the examples above). It is also possible for a Domain Name to exist
but not be connected to an actual machine. This is often done so that a
group or business can have an Internet email address without having to
establish a real Internet site. In these cases, some real Internet
machine must handle the mail on behalf of the listed Domain name.
|
| |
| DOS |
The
first personal computer DOS, called PC-DOS, was developed for IBM by
Bill Gates and his new Microsoft Corporation. He retained the rights to
market a Microsoft version, called MS-DOS. PC-DOS and MS-DOS are almost
identical and most users have referred to either of them as just "DOS."
DOS was (and still is) a non-graphical line-oriented command-driven
operating system, with a relatively simple interface but not overly
"friendly" user interface. Its prompt to enter a command looks like
this:
C:\>
The first Microsoft Windows operating system was really an application
that ran on top of the MS-DOS operating system. Today, Windows
operating systems continue to support DOS (or a DOS-like user
interface) for special purposes by emulating the operating system.
In the 1970s before the personal computer was invented, IBM had a
different and unrelated DOS (Disk Operating System) that ran on smaller
business computers. It was replaced by IBMs VSE operating system. |
| |
| DOWNLOAD |
The
process of copying data file(s) from a remote computer to a local
computer. The opposite action is upload where a local file is copied to
a server. |
| |
| E-COMMERCE |
E-commerce
(electronic commerce or EC) is the buying and selling of goods and
services on the Internet, especially the World Wide Web. In practice,
this term and a new term, "e-business," are often used interchangeably.
For online retail selling, the term e-tailing is sometimes used.
E-commerce can be divided into:
E-tailing or "virtual storefronts" on Web sites with online catalogs, sometimes gathered into a "virtual mall"
The gathering and use of demographic data through Web contacts
Electronic Data Interchange (EDI), the business-to-business exchange of data
email and fax and their use as media for reaching prospects and
established customers (for example, with newsletters)
Business-to-business buying and selling The security of business
transactions |
| |
| EMAIL |
Email
(electronic mail) is the exchange of computer-stored messages by
telecommunication. (Some publications spell it email; we prefer the
currently more established spelling of email.) Email messages are
usually encoded in ASCII text. However, you can also send non-text
files, such as graphic images and sound files, as attachments sent in
binary streams. Email was one of the first uses of the Internet and is
still the most popular use. A large percentage of the total traffic
over the Internet is email. Email can also be exchanged between online
service users and in networks other than the Internet, both public and
private.
Email can be
distributed to lists of people as well as to individuals. A shared
distribution list can be managed by using an email reflector. Some
mailing lists allow you to subscribe by sending a request to the
mailing list administrator. A mailing list that is administered
automatically is called a list server.
Email is one of the protocols included with the Transport Control
Protocol/Internet Protocol (TCP/IP) suite of protocols. A popular
protocol for sending email is SMTP and a popular protocol for receiving
it is POP3. Both Netscape and Microsoft include an email utility with
their Web browsers.
|
| |
| EMOTICONS |
On
the Internet in email, chatting, and posted messages, an emoticon
(sometimes referred to as a "smiley") is a short sequence of keyboard
letters and symbols, usually emulating a facial expression, expressing
a feeling that supplements the message. Most of these emoticons use
several symbols to create a small face with an expression such as a
smile, wink, or turned-down mouth.
One of our contributors says that to read these you can either tilt your head or turn the monitor on its side.
:-) Smile
;-) Smile with a wink
:<}) User with moustache, smiling
:-|| Mad
:-( Sad
%*@:-( Hung over
>:) Perplexed look
.) Keeping an eye out for you
8:-) Glasses on forehead
8:] Normal smiling face of a gorilla
0:-) Angel
:V) Duck
3:-o Cow
_8-(|) Homer Simpson
|:-)= Abe Lincoln
*<:-) Santa Claus
:)-) Scuba diver
:-{} User with heavy lipstick
>:-< Mad
*#:-) Scotsman wearing his Scottish tam
%-^ User is another Picasso
#-) User partied all night
<:I Dunce
:-| "Have an ordinary day!" Smiley
:}{: Kisses (stolen from June bug)
oooo(0) (0)oooo Toes
(-_-) Secret smile
#.-o "Oh, nooooooo Mr. Bill!!!" |
| |
| ETHERNET |
Ethernet
is the most widely-installed local area network technology. Now
specified in a standard, IEEE 802.3, Ethernet was originally developed
by Xerox and then developed further by Xerox, DEC, and Intel. An
Ethernet LAN typically uses coaxial cable or special grades of twisted
pair wires. The most commonly installed Ethernet systems are called
10BASE-T and provide transmission speeds up to 10 Mbps. Devices are
connected to the cable and compete for access using a Carrier Sense
Multiple Access with Collision Detection (CSMA/CD) protocol.
Fast Ethernet or 100BASE-T provides transmission speeds up to 100
megabits per second and is typically used for LAN backbone systems,
supporting workstations with 10BASE-T cards. Gigabit Ethernet provides
an even higher level of backbone support at 1000 megabits per second (1
gigabit or 1 billion bits per second).
|
| |
| FAQ |
The
FAQ (pronounced FAk) or list of "frequently-asked questions" (and
answers) has become a feature of the Internet. The FAQ seems to have
originated in many of the Usenet groups as a way to acquaint new users
with the rules. Today, there are thousands of FAQs on the World Wide
Web.
To see the range and
variety of topics for which FAQs have been written, go to Yahoo or any
major search engine, and enter "faq" or "faqs" in the search entry box.
To find a FAQ on a subject of interest (for example, hedgehogs), enter
"faq and hedgehogs"(without the quotes). Also note that the number of
subjects on which you will NOT find is FAQ is also large. The most
useful FAQs are often found at a Web site you |
| |
| FAX |
Sometimes
called "telecopying," a fax is the telephonic transmission of
scanned-in printed material (text or images), usually to a telephone
number associated with a printer or other output device. The original
document is scanned with a fax machine, which treats the contents (text
or images) as a single fixed graphic image, converting it into a
bitmap. In this digital form, the information is transmitted as
electrical signals through the telephone system. The receiving fax
machine reconverts the coded image and prints a paper copy of the
document.
Almost all modems
manufactured today are capable of sending and receiving fax data.
Fax/modem software generates fax signals directly from disk files or
the screen. Even if a document is text only, it is treated by the
computer as a scanned image and is transmitted to the receiver as a
bitmap. Faxing a message online works well if the recipient wants only
to read the message. However, if the document requires editing, it must
be converted into ASCII text by an OCR (optical character recognition)
program, or it must be retyped manually into the computer. A more
efficient method of sending documents that require modification is
through the email system. Email files are already ASCII text so they
can be edited immediately in any text editor or word processing
program.
The Internet now provides a new and cheaper way to send faxes in some
cases. A number of free and commercial companies provide arrangements
for using the Internet rather than the public telephone system for most
or part of the path to the fax point. Some services also provide the
ability to broadcast a fax to multiple addresses. We ourself offer
Fax2email services.
|
| |
| FDDI |
Fibre
Distributed Data Interface is a standard for transmitting data through
optical fibre cables at a rate of around 100 million bps. |
| |
| FILE EXTENSION |
1)
In computer operating systems, a file name extension is an optional
addition to the file name in a suffix of the form ".xxx" where "xxx"
represents a limited number of alphanumeric characters depending on the
operating system. (In Windows 3.1, for example, a file name extension
or suffix can have no more than three characters, but in Windows 95, it
can have more.) The file name extension allows a files format to be
described as part of its name so that users can quickly understand the
type of file it is without having to "open" or try to use it. The file
name extension also help/s an application program recognize whether a
file is a type that it can work with.
2) In programming, an extension is a file containing programming that
serves to extend the capabilities of or data available to a more basic
program. Extensions are sometimes required to be stored in a separate
extensions file so that they are easy to locate. When installing
software, you may be instructed to take one or more steps related to
installing extensions (or these steps may automatically be done for
you). |
| |
| FINGER |
Finger
is a program that tells you the name associated with an email address.
It may also tell you whether they are currently logged on at their
system or their most recent logon session and possibly other
information, depending on the data that is maintained about users on
that computer. Finger originated as part of BSD UNIX.
To finger another Internet user, you need to have the finger program on
your computer or you can go to a finger gateway on the Web and enter
the email address. The server at the other end must be set up to handle
finger requests. A ".plan" file can be created for any user that can be
fingered. Commonly, colleges, universities, and large corporations set
up a finger facility. Your own Internet access provider may also set up
information about you and other subscribers that someone else can
"finger." (To find out, enter your own email address at a finger
gateway.) |
| |
| FIREWALL |
A
firewall is a set of related programs, located at a network gateway
server, that protects the resources of a private network from users
from other networks. (The term also implies the security policy that is
used with the programs.) An enterprise with an intranet that allows its
workers access to the wider Internet installs a firewall to prevent
outsiders from accessing its own private data resources and for
controlling what outside resources its own users have access to.
Basically, a firewall, working closely with a router program, filters
all network packets to determine whether to forward them toward their
destination. A firewall also includes or works with a proxy server that
makes network requests on behalf of workstation users. A firewall is
often installed in a specially designated computer separate from the
rest of the network so that no incoming request can get directly at
private network resources.
There are a number of firewall screening methods. A simple one is to
screen requests to make sure they come from acceptable (previously
identified) domain names and IP addresses. For mobile users, firewalls
allow remote access in to the private network by the use of secure
logon procedures and authentication certificates.
A number of companies make firewall products. Features include logging
and reporting, automatic alarms at given thresholds of attack, and a
graphical user interface for controlling the firewall. |
| |
| FLAME |
Originally,
flame meant to carry forth in a passionate manner in the spirit of
honourable debate. Flames most often involved the use of flowery
language and flaming well was an art form. More recently flame has come
to refer to any kind of derogatory comment no matter how witless or
crude. |
| |
| FLAME WAR |
When
an online discussion degenerates into a series of personal attacks
against the debaters, rather than discussion of their positions. A
heated exchange. |
| |
| FREEWARE |
Freeware
is programming that is offered at no cost. However, it is copyrighted
so that you cant incorporate its programming into anything you may be
developing. The least restrictive "no-cost" programs are open to copy
programs in the public domain. These include a number of small UNIX
programs. When reusing public domain software in your own programs, its
good to know the history of the program so that you can be sure it
really is in the public domain. |
| |
| FTP |
FTP
(File Transfer Protocol), a standard Internet protocol, is the simplest
way to exchange files between computers on the Internet. Like the
Hypertext Transfer Protocol (HTTP), which transfers displayable Web
pages and related files, and the Simple Mail Transfer Protocol (SMTP),
which transfers email, FTP is an application protocol that uses the
Internets TCP/IP protocols. FTP is commonly used to transfer Web page
files from their creator to the computer that acts as their server for
everyone on the Internet. Its also commonly used to download programs
and other files to your computer from other servers.
As a user, you can use FTP with a simple command line interface (for
example, from the Windows MS-DOS Prompt window) or with a commercial
program that offers a graphical user interface. Your Web browser can
also make FTP requests to download programs you select from a Web page.
Using FTP, you can also update (delete, rename, move, and copy) files
at a server. You need to log on to an FTP server. However, publicly
available files are easily accessed using anonymous FTP.
Basic FTP support is usually provided as part of a suite of programs
that come with TCP/IP. However, any FTP client program with a graphical
user interface usually must be downloaded from the company that makes
it.
|
| |
| FUZZY LOGIC |
Fuzzy
logic is an approach to computing based on "degrees of truth" rather
than the usual "true or false" (1 or 0) Boolean logic on which the
modern computer is based. The idea of fuzzy logic was first advanced by
Dr. Lotfi Zadeh of the University of California at Berkeley in the
1960s. Dr. Zadeh was working on the problem of computer understanding
of natural language. Natural language (like most other activities in
life and indeed the universe) is not easily translated into the
absolute terms of 0 and 1. (Whether everything is ultimately
describable in binary terms is a philosophical question worth pursuing,
but in practice much data we might want to feed a computer is in some
state in between and so, frequently, are the results of computing.)
Fuzzy logic includes 0 and 1 as extreme cases of truth (or "the state
of matters" or "fact") but also includes the various states of truth in
between so that, for example, the result of a comparison between two
things could be not "tall" or "short" but ".38 of tallness."
Fuzzy logic seems closer to the way our brains work. We aggregate data
and form a number of partial truths which we aggregate further into
higher truths which in turn, when certain thresholds are exceeded,
cause certain further results such as motor reaction. A similar kind of
process is used in artificial computer neural networks and expert
systems. |
| |
| FYI |
FYI
(pronounced EFF-WAI-AI) is an abbreviation for "For your information,"
and is often used in forwarding email or printed material to colleagues
or friends. It usually means that information is simply being shared
and that no immediate action is required or expected. |
| |
| GATEWAY |
A
gateway is a network point that acts as an entrance to another network.
On the Internet, in terms of routing, the network consists of gateway
nodes and host nodes. The computers of network users and the computers
that serve content (such as Web pages) are host nodes. The computers
that control traffic within your companys network or at your local
Internet service provider (ISP) are gateway nodes.
In the network for an enterprise, a computer server acting as a gateway
node is often also acting as a proxy server and a firewall server.
Gateways also involve the use of routers and switches.
|
| |
| GIF |
A
GIF (the original and preferred pronunciation is DJIF) is one of the
two most common file formats for graphic images on the World Wide Web.
The other is the JPEG.
On the
Web and elsewhere on the Internet (for example, bulletin board
services), the GIF has become a de facto standard form of image. The
LZW compression algorithm used in the GIF format is owned by Unisys and
companies that make products that exploit the algorithm (including the
GIF format) need to license its use from Unisys. In practice, Unisys
has not required users of GIF images to obtain a license, although
their licensing statement indicates that it is a requirement. Unisys
says that getting a license from them does not necessarily involve a
fee.
Technically, a GIF uses the 2D raster data type, is encoded in binary,
and uses LZW compression. There are two versions of the format, 87a and
89a. Version 89a (July, 1989) allows for the possibility of an animated
GIF, which is a short sequence of images within a single GIF file. A
GIF89a can also be specified for interlaced presentation.
A patent-free replacement for the GIF, the PNG format, has been
developed by an Internet committee and major browsers support it or
soon will. Meanwhile, many GIF downloaders and Web site builders on the
Web continue to be ignorant of or indifferent to the requirement to get
a license from Unisys for the use of their algorithm.
|
| |
| GIGABYTE |
A
gigabyte (pronounced GIG-a-bite with hard Gs) is a measure of computer
data storage capacity and is "roughly" a billion bytes. A gigabyte is
two to the 30th power, or 1,073,741,824 in decimal notation. |
| |
| GOPHER |
Gopher
is an Internet application protocol in which hierarchically-organized
file structures are maintained on servers that themselves are part of
an overall information structure. Gopher provided a way to bring text
files from all over the world to a viewer on your computer. Popular for
several years, especially in universities, Gopher was a step toward the
World Wide Webs Hypertext Transfer Protocol (HTTP). With hypertext
links, the Hypertext Markup Language (HTML), and the arrival of a
graphical browser, Mosaic, the Web quickly transcended Gopher. Many of
the original file structures, especially those in universities, still
exist and can be accessed through most Web browsers (because they also
support the Gopher protocol). Gopher was developed at the University of
Minnesota, whose sports teams are called "the Golden Gophers."
Although most Gopher browsers and files are text-based, Gopher
browsers, notably HyperGopher, were developed that displayed graphic
images (GIF and JPEG files) that were included in Gopher file
directories. |
| |
| HACKER |
Hacker
is a term used by some to mean "a clever programmer" and by others,
especially journalists or their editors, to mean "someone who tries to
break into computer systems."
1) Eric Raymond, compiler of The New Hacker's Dictionary, defines a
hacker as a clever programmer. A "good hack" is a clever solution to a
programming problem and "hacking" is the act of doing it. Raymond lists
five possible characteristics that qualify one as a hacker, which we
paraphrase here:
A person who enjoys learning details of a programming language or system
A person who enjoys actually doing the programming rather than just theorizing about it.
A person capable of appreciating someone else's hacking.
A person who picks up programming quickly.
A person who is an expert at a particular programming language or system, as in "UNIX hacking"
Raymond deprecates the use of this term for someone who attempts to
crack someone else's system or otherwise uses programming or expert
knowledge to act maliciously. He prefers the term cracker for this
meaning.
2) Journalists or their editors almost universally use hacker to mean
someone who attempts to break into computer systems. Typically, this
kind of hacker would be a proficient programmer or engineer with
sufficient technical knowledge to understand the weak points in a
security system. |
| |
| HELPER APPLICATION |
A
program allowing you to view multimedia files that your web browser
cannot handle internally, such as images, audio and video files. The
file must be downloaded before it will be displayed/played. Plug-ins
allow you to actually view the file over the Internet without
downloading first. |
| |
| HIT |
A
hit is a single file request in the log of a Web server. A request for
an HTML page with three graphic images will result in four hits in the
log: one for the HTML file and one for each of the graphic image files.
While a hit is a meaningful measure of how much traffic a server
handles, it can be a misleading indicator of how many pages are being
looked at. Instead, advertising agencies and their clients look at the
number of pages delivered and ad impressions or views. |
| |
| HOMEPAGE |
Several
meanings. Originally, the web page that your browser is set to use when
it starts up. The more common meaning refers to the main web page for a
business, organization, person or simply the main page out of a
collection of web pages, e.g. “Check out so-and-so's new Home Page.” |
| |
| HOST |
The term "host" is used in several contexts, in each of which it has a slightly different meaning:
1) On the Internet, the term "host" means any computer that has full
two-way access to other computers on the Internet. A host has a
specific "local or host number" that, together with the network number,
forms its unique Internet Protocol address. If you use PPP to get
access to your access provider, you have a unique IP address for the
duration of any connection you make to the Internet and your computer
is a host for that period. In this context, a "host" is a node in a
network.
2) In IBM and perhaps other mainframe computer environments, a host is
a mainframe computer (which is now usually referred to as a "large
server"). In this context, the mainframe has intelligent or "dumb"
workstations attached to it that use it as a host provider of services.
(This does not mean that the host only has "servers" and the
workstations only have "clients." The server/client relationship is a
programming model independent of this contextual usage of "host.")
3) In other contexts, the term generally means a device or program that
provides services to some smaller or less capable device or program. |
| |
| HTML |
HTML
(Hypertext Markup Language) is the set of "markup" symbols or codes
inserted in a file intended for display on a World Wide Web browser.
The markup tells the Web browser how to display a Web pages words and
images for the user. The individual markup codes are referred to as
elements (but many people also refer to them as tags).
HTML is a standard recommended by the World Wide Web Consortium (W3C)
and adhered to by the major browsers, Microsofts Internet Explorer and
Netscapes Navigator, which also provide some additional non-standard
codes. The current version of HTML is HTML 4. However, both Internet
Explorer and Netscape implement some features differently and provide
non-standard extensions. Web developers using the more advanced
features of HTML 4 may have to design pages for both browsers and send
out the appropriate version to a user. Significant features in HTML 4
are sometimes described in general as dynamic HTML. What is sometimes
referred to as HTML 5 is an extensible form of HTML called XHTML.
|
| |
| HTTP |
The
Hypertext Transfer Protocol (HTTP) is the set of rules for exchanging
files (text, graphic images, sound, video, and other multimedia files)
on the World Wide Web. Relative to the TCP/IP suite of protocols (which
are the basis for information exchange on the Internet), HTTP is an
application protocol.
Essential
concepts that are part of HTTP include (as its name implies) the idea
that files can contain references to other files whose selection will
elicit additional transfer requests. Any Web server machine contains,
in addition to the HTML and other files it can serve, an HTTP daemon, a
program that is designed to wait for HTTP requests and handle them when
they arrive. Your Web browser is an HTTP client, sending requests to
server machines. When the browser user enters file requests by either
"opening" a Web file (typing in a Uniform Resource Locator or URL) or
clicking on a hypertext link, the browser builds an HTTP request and
sends it to the Internet Protocol address indicated by the URL. The
HTTP daemon in the destination server machine receives the request and,
after any necessary processing, the requested file is returned. |
| |
| HUB |
In
general, a hub is the central part of a wheel where the spokes come
together. The term is familiar to frequent fliers who travel through
airport "hubs" to make connecting flights from one point to another. In
data communications, a hub is a place of convergence where data arrives
from one or more directions and is forwarded out in one or more other
directions. A hub usually includes a switch of some kind. (And a
product that is called a "switch" could usually be considered a hub as
well.) The distinction seems to be that the hub is the place where data
comes together and the switch is what determines how and where data is
forwarded from the place where data comes together. Regarded in its
switching aspects, a hub can also include a router.
1) In describing network topologies, a hub topology consists of a
backbone (main circuit) to which a number of outgoing lines can be
attached ("dropped"), each providing one or more connection ports for
devices to attach to. For Internet users not connected to a local area
network, this is the general topology used by your access provider.
Other common network topologies are the bus network and the ring
network. (Either of these could possibly feed into a hub network, using
a bridge.)
2) As a network product, a hub may include a group of modem cards for
dial-in users, a gateway card for connections to a local area network
(for example, an Ethernet or a Token Ring), and a connection to a T-1
line (the main line in this example). |
| |
| HYPERTEXT |
Hypertext
is the organization of information units into connected associations
that a user can choose to make. An instance of such an association is
called a link or hypertext link. (And the highlighted word "link" in
the previous sentence is an example of a hypertext link.)
Hypertext was the main concept that led to the invention of the World
Wide Web, which is, after all, nothing more (or less) than an enormous
amount of information content connected by an enormous number of
hypertext links. |
| |
| ICMP |
ICMP
is a message control and error-reporting protocol between a host server
and a gateway to the Internet. ICMP uses Internet Protocol (IP)
datagrams, but the messages are processed by the IP software and are
not directly apparent to the application user. |
| |
| IMAP |
IMAP
(Internet Message Access Protocol) is a standard protocol for accessing
email from your local server. IMAP (the latest version is IMAP4) is a
client/server protocol in which email is received and held for you by
your Internet server. You (or your email client) can view just the
heading and the sender of the letter and then decide whether to
download the mail. You can also create and manipulate folders or
mailboxes on the server, delete messages, or search for certain parts
or an entire note. IMAP requires continual access to the server during
the time that you are working with your mail.
A less sophisticated protocol is POP3 (Post Office Protocol 3). With
POP3, your mail is saved for you in your mail box on the server. When
you read your mail, all of it is immediately downloaded to your
computer and no longer maintained on the server.
IMAP can be thought of as a remote file server. POP can be thought of as a "store-and-forward" service.
POP and IMAP deal with the receiving of email from your local server
and are not to be confused with SMTP, a protocol for transferring email
between points on the Internet. You send email with SMTP and a mail
handler receives it on your recipient's behalf. Then the mail is read
using POP or IMAP. |
| |
| IMHO |
In
My Humble Opinion -- A shorthand appended to a comment written in an
online forum, IMHO indicates that the writer is aware that they are
expressing a debatable view, probably on a subject already under
discussion. One of many such shorthand's in common use online,
especially in discussion forums and chat areas. |
| |
| INFORMATION SUPERHIGHWAY INFOBAHN |
The
terms were coined to describe a possible upgrade to the existing
Internet through the use of fiber optic and/or coaxial cable to allow
for high speed data transmission. This highway does not exist - the
Internet of today is not an information superhighway. |
| |
| iNTERNET |
Lower case i Any time you connect 2 or more networks together, you have an internet - as in inter-national or inter-state. |
| |
| INTERNET |
The
Internet, sometimes called simply "the Net," is a worldwide system of
computer networks - a network of networks in which users at any one
computer can, if they have permission, get information from any other
computer (and sometimes talk directly to users at other computers). It
was conceived by the Advanced Research Projects Agency (ARPA) of the
U.S. government in 1969 and was first known as the ARPANet. The
original aim was to create a network that would allow users of a
research computer at one university to be able to "talk to" research
computers at other universities. A side benefit of ARPANets design was
that, because messages could be routed or rerouted in more than one
direction, the network could continue to function even if parts of it
were destroyed in the event of a military attack or other disaster.
Today, the Internet is a public, cooperative, and self-sustaining
facility accessible to hundreds of millions of people worldwide.
Physically, the Internet uses a portion of the total resources of the
currently existing public telecommunication networks. Technically, what
distinguishes the Internet is its use of a set of protocols called
TCP/IP (Transmission Control Protocol/Internet Protocol). Two recent
adaptations of Internet technology, the intranet and the extranet, also
make use of the TCP/IP protocol.
For many Internet users, electronic mail (email) has practically
replaced the Postal Service for short written transactions. Electronic
mail is the most widely used application on the Net. You can also carry
on live "conversations" with other computer users, using IRC (Internet
Relay Chat). More recently, Internet telephony hardware and software
allows real-time voice conversations.
The most widely used part of the Internet is the World Wide Web (often
abbreviated "WWW" or called "the Web"). Its outstanding feature is
hypertext, a method of instant cross-referencing. In most Web sites,
certain words or phrases appear in text of a different color than the
rest; often this text is also underlined. When you select one of these
words or phrases, you will be transferred to the site or page that is
relevant to this word or phrase. Sometimes there are buttons, images,
or portions of images that are "clickable." If you move the pointer
over a spot on a Web site and the pointer changes into a hand, this
indicates that you can click and be transferred to another site.
Using the Web, you have access to millions of pages of information. Web
"surfing" is done with a Web browser, the most popular of which are
Netscape Navigator and Microsoft Internet Explorer. The appearance of a
particular Web site may vary slightly depending on the browser you use.
Also, later versions of a particular browser are able to render more
"bells and whistles" such as animation, virtual reality, sound, and
music files, than earlier versions. |
| |
| INTRANET |
An
intranet is a private network that is contained within an enterprise.
It may consist of many interlinked local area networks and also use
leased lines in the wide area network. Typically, an intranet includes
connections through one or more gateway computers to the outside
Internet. The main purpose of an intranet is to share company
information and computing resources among employees. An intranet can
also be used to facilitate working in groups and for teleconferences.
An intranet uses TCP/IP, HTTP, and other Internet protocols and in
general looks like a private version of the Internet. With tunnelling,
companies can send private messages through the public network, using
the public network with special encryption/decryption and other
security safeguards to connect one part of their intranet to another.
Typically, larger enterprises allow users within their intranet to
access the public Internet through firewall servers that have the
ability to screen messages in both directions so that company security
is maintained. When part of an intranet is made accessible to
customers, partners, suppliers, or others outside the company, that
part becomes part of an extranet.
Note that an Intranet may not actually be an internet -- it may simply be a network. |
| |
| IP ADDRESS |
The
Internet Protocol (IP) is the method or protocol by which data is sent
from one computer to another on the Internet. Each computer (known as a
host) on the Internet has at least one address that uniquely identifies
it from all other computers on the Internet. When you send or receive
data (for example, an email note or a Web page), the message gets
divided into little chunks called packets. Each of these packets
contains both the senders Internet address and the receivers address.
Any packet is sent first to a gateway computer that understands a small
part of the Internet. The gateway computer reads the destination
address and forwards the packet to an adjacent gateway that in turn
reads the destination address and so forth across the Internet until
one gateway recognizes the packet as belonging to a computer within its
immediate neighborhood or domain. That gateway then forwards the packet
directly to the computer whose address is specified.
Because a message is divided into a number of packets, each packet can,
if necessary, be sent by a different route across the Internet. Packets
can arrive in a different order than the order they were sent in. The
Internet Protocol just delivers them. Its up to another protocol, the
Transmission Control Protocol (TCP) to put them back in the right
order.
IP is a connectionless protocol, which means that there is no
established connection between the end points that are communicating.
Each packet that travels through the Internet is treated as an
independent unit of data without any relation to any other unit of
data. (The reason the packets do get put in the right order is because
of TCP, the connection-oriented protocol that keeps track of the packet
sequence in a message.) In the Open Systems Interconnection (OSI)
communication model, IP is in layer 3, the Networking Layer.
The most widely used version of IP today is Internet Protocol Version 4
(IPv4). However, IP Version 6 (IPv6) is also beginning to be supported.
IPv6 provides for much longer addresses and therefore for the
possibility of many more Internet users. IPv6 includes the capabilities
of IPv4 and any server that can support IPv6 packets can also support
IPv4 packets. |
| |
| IPS TAG |
The actual true meaning of IPS Tag was
created and lost with Nominet UK's predecesor the Naming Commitee, however it is
widely accepted that it probably stands for Internet Provider Security Tag. |
| |
| IPX |
IPX
(Internetwork Packet Exchange) is a networking protocol from Novell
that interconnects networks that use Novells NetWare clients and
servers. IPX is a datagram or packet protocol. IPX works at the network
layer of communication protocols and is connectionless (that is, it
does not require that a connection be maintained during an exchange of
packets as, for example, a regular voice phone call does).
Packet acknowledgment is managed by another Novell protocol, the
Sequenced Packet Exchange™ (SPX). Other related Novell NetWare
protocols are: the Routing Information Protocol (RIP), the Service
Advertising Protocol (SAP), and the NetWare Link Services Protocol
(NLSP). |
| |
| IRC |
Internet
Relay Chat (IRC) is a system for chatting that involves a set of rules
and conventions and client/server software. On the Web, certain sites
such as Talk City or IRC networks such as the Undernet provide servers
and help you download an IRC client to your PC. Talk City also offers
an IRC client applet that it downloads for you as part of their home
page so that you can start chatting right away.
You can start a chat group (called a channel) or join an existing one.
There is a protocol for discovering existing chat groups and their
members. Depending on the type of network, nicknames can be reserved
(registered) or just used during the session. Some channels encourage
you to register a nickname that you always use and even offer space for
a personal profile, picture, and personal home page link.
The IRC protocol uses TCP (you can IRC via a Telnet client), usually on port 6667. |
| |
| ISDN |
Integrated
Services Digital Network (ISDN) is a set of CCITT/ITU standards for
digital transmission over ordinary telephone copper wire as well as
over other media. Home and business users who install ISDN adapters (in
place of their modems) can see highly-graphic Web pages arriving very
quickly (up to 128 Kbps). ISDN requires adapters at both ends of the
transmission so your access provider also needs an ISDN adapter. ISDN
is generally available from your phone company in most urban areas in
the United States and Europe.
There are two levels of service: the Basic Rate Interface (BRI),
intended for the home and small enterprise, and the Primary Rate
Interface (PRI), for larger users. Both rates include a number of B
(bearer) channels and a D (delta) channel. The B channels carry data,
voice, and other services. The D channel carries control and signalling
information.
The Basic Rate Interface consists of two 64 Kbps B channels and one 16
Kbps D channel. Thus, a Basic Rate user can have up to 128 Kbps
service. The Primary Rate consists of 23 B channels and one 64 Kpbs D
channel in the United States or 30 B channels and 1 D channel in
Europe.
The typical cost for Basic Rate usage in a city like Kingston, New York
is about $125 for phone company installation, $300 for the ISDN
adapter, and an extra $20 a month for a line that supports ISDN.
Integrated Services Digital Network in concept is the integration of
both analog or voice data together with digital data over the same
network. Although the ISDN you can install is integrating these on a
medium designed for analog transmission, broadband ISDN (BISDN) will
extend the integration of both services throughout the rest of the
end-to-end path using fiber optic and radio media. Broadband ISDN will
encompass frame relay service for high-speed data that can be sent in
large bursts, the Fiber Distributed-Data Interface (FDDI), and the
Synchronous Opical Network (SONET). BISDN will support transmission
from 2 Mbps up to much higher, but as yet unspecified, rates. |
| |
| ISP |
An
ISP (Internet service provider) is a company that provides individuals
and other companies access to the Internet and other related services
such as Web site building and hosting. An ISP has the equipment and the
telecommunication line access required to have points-of-presence on
the Internet for the geographic area served. The larger ISPs have their
own high-speed leased lines so that they are less dependent on the
telecommunication providers and can provide better service to their
customers. Among the largest national and regional ISPs are AT&T
WorldNet, IBM Global Network, MCI, Netcom, UUNet, and PSINet.
ISPs also include regional providers such as New Englands NEARNet and
the San Francisco Bay area BARNet. They also include thousands of local
providers. In addition, Internet users can also get access through
online service providers (OSPs) such as America Online and Compuserve.
The larger ISPs interconnect with each other through MAEs (ISP
switching centres run by MCI WorldCom) or similar centers. The
arrangements they make to exchange traffic are known as peering
agreements. There are several very comprehensive lists of ISPs
world-wide available on the Web.
An ISP is also sometimes referred to as an IAP (Internet access
provider). ISP is sometimes used as an abbreviation for independent
service provider to distinguish a service provider that is an
independent, separate company from a telephone company.
|
| |
| IT |
IT
(information technology) is a term that encompasses all forms of
technology used to create, store, exchange, and use information in its
various forms (business data, voice conversations, still images, motion
pictures, multimedia presentations, and other forms, including those
not yet conceived). It's a convenient term for including both telephony
and computer technology in the same word. It is the technology that is
driving what has often been called "the information revolution." |
| |
| JAVA |
Java
is a programming language expressly designed for use in the distributed
environment of the Internet. It was designed to have the "look and
feel" of the C++ language, but it is simpler to use than C++ and
enforces a completely object-oriented view of programming. Java can be
used to create complete applications that may run on a single computer
or be distributed among servers and clients in a network. It can also
be used to build small application modules or applets for use as part
of a Web page. Applets make it possible for a Web page user to interact
with the page.
The major characteristics of Java are:
The programs you create are portable in a network. Your program is
compiled into Java bytecode that can be run anywhere in a network on a
server or client that has a Java virtual machine. The Java virtual
machine interprets the bytecode into code that will run on the real
computer hardware. This means that individual computer platform
differences such as instruction lengths can be recognised and
accommodated locally just as the program is being executed.
Platform-specific versions of your program are no longer needed.
The code is "robust," here meaning that, unlike programs written in C++
and perhaps some other languages, the Java objects can contain no
references to data external to themselves or other known objects. This
ensures that an instruction cannot contain the address of data storage
in another application or in the operating system itself, either of
which would cause the program and perhaps the operating system itself
to terminate or "crash." The Java virtual machine makes a number of
checks on each object to ensure integrity.
Java is object-oriented, which means that, among other characteristics,
similar objects can take advantage of being part of the same class and
inherit common code. Objects are thought of as "nouns" that a user
might relate to rather than the traditional procedural "verbs." A
method can be thought of as one of the objects capabilities or
behaviors.
In addition to being executed at the client rather than the server, a
Java applet has other characteristics designed to make it run fast.
Relative to C++, Java is easier to learn. (However, it is not a language you will pick up in an evening!)
Java was introduced by Sun Microsystems in 1995 and instantly created a
new sense of the interactive possibilities of the Web. Both of the
major Web browsers include a Java virtual machine. Almost all major
operating system developers (IBM, Microsoft, and others) have added
Java compilers as part of their product offerings.
The Java virtual machine includes an optional just-in-time (JIT)
compiler that dynamically compiles bytecode into executable code as an
alternative to interpreting one bytecode instruction at a time. In many
cases, the dynamic JIT compilation is faster than the virtual machine
interpretation.
JavaScript should not be confused with Java. JavaScript, which
originated at Netscape, is interpreted at a higher level, is easier to
learn than Java, but lacks some of the portability of Java and the
speed of bytecode. Because Java applets will run on almost any
operating system without requiring recompilation and because Java has
no operating system-unique extensions or variations, Java is generally
regarded as the most strategic language in which to develop
applications for the Web. (However, JavaScript can be useful for very
small applications that run on the Web client or server.) |
| |
| JDK |
Java
Development Kit -- A software development package from Sun Microsystems
that implements the basic set of tools needed to write, test and debug
Java applications and applets See Also: Applet , Java. |
| |
| JPEG |
A
JPEG (pronounced JAY-peg) is a graphic image created by choosing from a
range of compression qualities (actually, from one of a suite of
compression algorithms). When you create a JPEG or convert an image
from another format to a JPEG, you are asked to specify the quality of
image you want. Since the highest quality results in the largest file,
you can make a trade-off between image quality and file size. Formally,
the JPEG file format is ISO standard 10918. The JPEG scheme includes 29
distinct coding processes although a JPEG implementer may not use them
all.
Along with the Graphic
Interchange Format (GIF) file, the JPEG is a file type supported by the
World Wide Web protocol, usually with the file suffix of ".jpg". You
can create a progressive JPEG that is similar to an interlaced GIF. |
| |
| K-FLEX |
Rockwell Corporation |
| |
| KERMIT |
Kermit
is a popular file transfer and management protocol and suite of
communications software programs with advantages over existing Internet
protocols such as FTP and Telnet. It is freeware, developed and
maintained by members of the Kermit Project at Columbia University.
(However, you are invited to purchase shrink-wrapped versions and/or
the manuals to help support the project.) The Kermit protocol is
described as "fast, robust, extensible, tunable, and
medium-independent." In addition to the protocol support, the Kermit
suite includes terminal emulation, character-set translation, and
scripting. The suite can be installed on almost any operating system,
including Windows, UNIX, DOS, VMS, OS/2, and a number of mainframe
operating systems. Most versions support both direct or dialled serial
connections (with a modem) and network connections (Telnet and often
others such as Rlogin, LAT, or X.25).
Some advantages of Kermit are:
You can write a script that will allow a sequence of file transfers to happen with a single command
You can transfer an entire file directory and its subdirectories with a single command
Text and binary files can be sent in the same file transfer
Character-sets can be translated as part of the transfer (for example, from EBCDIC to ASCII)
Files can be transferred through firewall and network address translators |
| |
| KERNEL |
The
kernel is the essential center of a computer operating system, the core
that provides basic services for all other parts of the operating
system. A synonym is nucleus. A kernel can be contrasted with a shell,
the outermost part of an operating system that interacts with user
commands. Kernel and shell are terms used more frequently in UNIX and
some other operating systems than in IBM mainframe systems.
Typically, a kernel (or any comparable center of an operating system)
includes an interrupt handler that handles all requests or completed
I/O operations that compete for the kernel's services, a scheduler that
determines which programs share the kernel's processing time in what
order, and a supervisor that actually gives use of the computer to each
process when it is scheduled. A kernel may also include a manager of
the operating system's address spaces in memory or storage, sharing
these among all components and other users of the kernel's services. A
kernel's services are requested by other parts of the operating system
or by applications through a specified set of program interfaces
sometimes known as system calls.
Because the code that makes up the kernel is needed continuously, it is
usually loaded into computer storage in an area that is protected so
that it will not be overlaid with other less frequently used parts of
the operating system.
The kernel is not to be confused with the Basic Input/Output System (BIOS).
Some kernels have been developed independently for use in any operating
system that wants to use it. A well-known example is the Mach kernel,
developed at Carnegie-Mellon University, and currently used in a
version of the Linux operating system for Apple's PowerMac computers.
|
| |
| KILOBYTE |
As
a measure of computer memory or storage, a kilobyte (KB or Kbyte*) is
approximately a thousand bytes (actually, 2 to the 10th power, or
decimal 1,024 bytes). |
| |
| LAMER |
Lamer
is a term used on interactive Web sites to describe an irritating or
immature participant. Among users of Internet Relay Chat (IRC), a lamer
is someone who irritates other users by typing in all caps or iN pART
cAPS, by insulting and flaming other users, by typing abbreviations for
almost every word, or by performing other annoying acts in chat rooms.
Some IRC channels use bots to monitor any "lame" behaviour and kick
lamers out.
Lamer is also used
by crackers and warez d00dz. Warez d00dz (that is, "wares dudes") are
people who strip software of its copyright protection and then
distribute the pirated software on the Internet for downloading. Warez
d00dz sometimes compete to distribute the pirated software before other
warez d00dz groups. People who create warez sites sometimes call them
"warez sitez" and use "z" in other pluralizations. A lamer according to
the warez d00dz culture is an individual who tries to distribute
software that is several years old or software infected with a virus.
Crackers use the term in a non-derogatory way to refer to cracker
aspirants who are in the larval or beginning stage of computer cracking. |
| |
| LAN |
A
local area network (LAN) is a group of computers and associated devices
that share a common communications line and typically share the
resources of a single processor or server within a small geographic
area (for example, within an office building). Usually, the server has
applications and data storage that are shared in common by multiple
computer users. A local area network may serve as few as two or three
users (for example, in a home network) or many as thousands of users
(for example, in an FDDI network).
The main local area network technologies are:
Ethernet
Token ring
ARCNET
FDDI (Fiber Distributed Data Interface)
Typically, a suite of application programs can be kept on the LAN
server. Users who need an application frequently can download it once
and then run it from their local hard disk. Users can order printing
and other services as needed through applications run on the LAN
server. A user can share files with others at the LAN server; read and
write access is maintained by a LAN administrator.
A LAN server may also be used as a Web server if safeguards are taken
to secure internal applications and data from outside access.
|
| |
| LEASED LINE |
A
leased line is a telephone line that has been leased for private use.
In some contexts, its called a dedicated line. A leased line is usually
contrasted with a switched line or dial-up line.
Typically, large companies rent leased lines from the telephone message
carriers (such as AT&T) to interconnect different geographic
locations in their company. The alternative is to buy and maintain
their own private lines or, increasingly perhaps, to use the public
switched lines with secure message protocols. (This is called
tunneling.)
|
| |
| LINUX |
Linux
(often pronounced LIH-nuhks with a short "i") is a UNIX-like operating
system that was designed to provide personal computer users a free or
very low-cost operating system comparable to traditional and usually
more expensive UNIX systems. Linux has a reputation as a very efficient
and fast-performing system. Linux's kernel (the central part of the
operating system) was developed by Linus Torvalds at the University of
Helsinki in Finland. To complete the operating system, Torvalds and
other team members made use of system components developed by members
of the Free Software Foundation for the GNU project.
Linux is a remarkably complete operating system, including a graphical
user interface, X Window System, TCP/IP, the Emacs editor, and other
components usually found in a comprehensive UNIX system. Although
copyrights are held by various creators of Linux's components, Linux is
distributed using the Free Software Foundation's copyleft stipulations
that mean any copy is in turn freely available to others.
Unlike Windows and other proprietary systems, Linux is publicly open
and extendible by contributors. Because it conforms to the POSIX
standard user and programming interfaces, developers can write programs
that can be ported to other operating systems, including IBM's OS/390
running UNIX. Linux comes in versions for all the major microprocessor
platforms including the Intel, PowerPC, Sparc, and Alpha platforms.
Linux is distributed commercially by a number of companies. A magazine,
Linux Journal, is published as well as a number of books and pocket
references.
Linux is sometimes suggested as a possible publicly-developed
alternative to the desktop predominance of Microsoft Windows. Although
Linux is popular among users already familiar with UNIX, it remains far
behind Windows in numbers of users. |
| |
| LISTSERV |
Listserv,
like Majordomo, is a small program that automatically redistributes
email to names on a mailing list. Users can subscribe to a mailing list
by sending an email note to a mailing list they learn about; listserv
will automatically add the name and distribute future email postings to
every subscriber. (Requests to subscribe and unsubscribe are sent to a
special address so that all subscribers do not see these requests.)
These programs are also known as list servers. |
| |
| LOGIN |
In
general computer usage, logon is the procedure used to get access to an
operating system or application, usually in a remote computer. Almost
always a logon requires that the user have (1) a user ID and (2) a
password. Often, the user ID must conform to a limited length such as
16 characters and the password must contain at least one digit and not
match a natural language word. The user ID can be freely known and is
visible when entered at a keyboard or other input device. The password
must be kept secret (and is not displayed as it is entered). A similar
procedure, called registration, is required to enter some Web sites.
Logon is also used as a modifier as in "logon procedure." The verb form is two words: to log on.
In UNIX-based operating systems, logon is called login. The procedure
is called "the login procedure." and the verb form is: to log in. |
| |
| LOL |
Abbreviation of laugh out loud, commonly used online or on IRC. |
| |
| LURKING |
The
act of reading through mail lists and newsgroups without posting any
messages. Considered good netiquette to get the feel of the topic
before adding your own two penneth |
| |
| MAILING LIST |
A
mailing list is a list of people who subscribe to a periodic mailing
distribution on a particular topic. On the Internet, mailing lists
include each perso |
| |
| MAILSERVER |
The computer (and software running on it) that allows sorting and retrieval of Email messages. |
| |
| MEGABYTE |
1)
As a measure of computer processor storage and real and virtual memory,
a megabyte (abbreviated MB) is 2 to the 20th power bytes, or 1,048,576
bytes in decimal notation.
2)
According to the IBM Dictionary of Computing, when used to describe
disk storage capacity and transmission rates, a megabyte is 1,000,000
bytes in decimal notation.
According to the Microsoft Press Computer Dictionary, a megabyte means either 1,000,000 bytes or 1,048,576 bytes.
According to Eric S. Raymond in The New Hackers Dictionary, a megabyte
is always 1,048,576 bytes on the argument that bytes should naturally
be computed in powers of two. |
| |
| MHz |
A
megahertz (MHz or sometimes Mhz) is a million cycles of electromagnetic
currency alternation per second and is used as a unit of measure for
the "clock speed" of computer microprocessors. In designing computer
bus architectures, the microprocessor speed is considered together with
the potential speed or amount of data that can come into the computer
from I/O devices in order to optimise overall computer performance. |
| |
| MIME |
MIME
(Multi-Purpose Internet Mail Extensions) is an extension of the
original Internet email protocol that lets people use the protocol to
exchange different kinds of data files on the Internet: audio, video,
images, application programs, and other kinds, as well as the ASCII
handled in the original protocol, the Simple Mail Transport Protocol
(SMTP). In 1991, Nathan Borenstein of Bellcore proposed to the Internet
Engineering Task Force that SMTP be extended so that Internet (but
mainly Web) clients and servers could recognize and handle other kinds
of data than ASCII text. As a result, new file types were added to
"mail" as a supported Internet Protocol file type.
Servers insert the MIME header at the beginning of any Web
transmission. Clients use this header to select an appropriate
"player\" application for the type of data the header indicates. Some
of these players are built into the Web client or browser (for example,
all browsers come with GIF and JPEG image players as well as the
ability to handle HTML files); other players may need to be downloaded.
New MIME data types are registered with the Internet Assigned Numbers Authority (IANA).
MIME is specified in detail in Internet RFCs 1521 and 1522, which amend
the original mail protocol specification, RFC 821 (the Simple Mail
Transport Protocol) and the ASCII messaging header, RFC 822. |
| |
| MIRROR |
A
mirror site is a Web site or set of files on a computer server that has
been copied to another computer server in order to reduce network
traffic, ensure better availability of the Web site or files, or make
the site or downloaded files arrive more quickly for users close to the
mirror site. Mirroring is the practice of creating and maintaining
mirror sites.
A mirror site is
an exact replica of the original site and is usually updated frequently
to ensure that it reflects the content of the original site. Mirror
sites are used to make access faster when the original site may be
geographically distant (for example, a much-used Web site in Germany
may arrange to have a mirror site in the United States). In some cases,
the original site (for example, on a small university server) may not
have a high-speed connection to the Internet and may arrange for a
mirror site at a larger site with higher-speed connection and perhaps
closer proximity to a large audience.
In addition to mirroring Web sites, you can also mirror files that can
be downloaded from an FTP server. Netscape, Microsoft, Sun
Microsystems, and other companies have mirror sites from which you can
download their browser software.
Mirroring could be considered a static form of content delivery. |
| |
| MODEM |
A
modem modulates outgoing digital signals from a computer or other
digital device to analog signals for a conventional copper twisted-pair
telephone line and demodulates the incoming analog signal and converts
it to a digital signal for the digital device.
In recent years, the 2400 bps modem that could carry email has become
obsolete. 14.4 Kbps and 28.8 Kbps modems were temporary landing places
on the way to the much higher bandwidth devices and carriers of
tomorrow. From early 1998, most new personal computers came with 56
Kbps modems. By comparison, using a digital ISDN adapter instead of a
conventional modem, the same telephone wire can now carry up to 128
Kbps. With Digital Subscriber Line (DSL) systems, now being deployed in
a number of communities, bandwidth on twisted-pair can be in the
megabit range.
|
| |
| MOO |
A MOO is an object-oriented MUD. According to Canton Becker, author of "The Unofficial Moo Guide Tutorial," a MOO is:
"...just a programming language in which you design objects. Everything
is an object. Rooms are objects, exits are objects, possessions are
objects, even your MOO alter-ego/avatar is an object. We will be
looking at how you (1) make objects, and (2) write verbs that allow you
to do Interesting Things with those objects. Im not going to talk too
much about the philosophy of object-oriented programming (thats what
the OO in MOO stands for) so lets go ahead and make your first object:"
Canton Beckers first example (of creating an object) looks like this:
@create $thing called kleenex
You can then go on to relate the object to other objects and define the
verbs that work with the object (which is given a number by the MOO
server). Effectively, you can set up how other MOO participants will be
able to use or view your object. |
| |
| MP3 |
MP3
(MPEG-1 Audio Layer-3) is a standard technology and format for
compressing a sound sequence into a very small file (about one-twelfth
the size of the original file) while preserving the original level of
sound quality when it is played. MP3 files (identified with the file
name suffix of ".mp3") are available for downloading from a number of
Web sites. Many Windows 98 users will find that they have a player
built into their operating system. Otherwise, you can download a player
from one of several popular MP3 sites. MP3 files are usually
download-and-play files rather than streaming sound files that you
link-and-listen-to with RealPlayer and similar products (However,
streaming MP3 is possible.) Winamp (PC), MacAmp (Mac), and mpeg123
(UNIX) are popular MP3 players, but there are many others. To create an
MP3 file, you use a program called a ripper to get a selection from a
CD onto your hard drive and another program called an encoder to
convert the selection to an MP3 file. Most people, however, simply
download MP3s from someone else and play them. |
| |
| MPG or MPEG |
MPEG
(pronounced EHM-pehg), the Moving Picture Experts Group, develops
standards for digital video and digital audio compression. It operates
under the auspices of the International Oganization for Standardization
(ISO). The MPEG standards are an evolving series, each designed for a
different purpose.
To use MPEG
video files, you need a personal computer with sufficient processor
speed, internal memory, and hard disk space to handle and play the
typically large MPEG file (which has a file name suffix of .mpg). You
also need an MPEG viewer or client software that plays MPEG files.
(Note that .mp3 file suffixes indicate MP3 (MPEG-1 audio layer-3)
files, not MPEG-3 standard files.) You can download shareware or
commercial MPEG players from a number of sites on the Web. |
| |
| MUD |
A
MUD or Multi-User Dungeon is an inventively structured social
experience on the Internet, managed by a computer program and often
involving a loosely organized context or theme, such as a rambling old
castle with many rooms or a period in national history. Some MUDs are
ongoing adventure games; others are educational in purpose; and others
are simply social. MUDs existed prior to the World Wide Web, accessible
through telneting to a computer that hosted the MUD. Today, many MUDs
can be accessed through a Web site and some are perhaps better known as
3-D worlds or chat worlds.
MUD
participants adopt a character or avatar when they join or log in to a
MUD. Typically, you can describe your avatar to the other participants.
Each MUD has its own name, special character and ambience, and set of
rules. MUDs are run by advanced participants or programmers called
wizards.
Although many MUDs continue to be entirely text-based, some new MUDs
use virtual reality settings and you can see the characters. However,
the focus is on the exchange of text between participants who are
logged in at a particular time. There are a number of variations on the
MUD, including MOOs, MUCKs, and MUSHes, each associated with a server
program of that name and varied mainly by the programming language used
and the capabilities offered.
|
| |
| MUSE |
Multi-User Simulated Environment -- One kind of MUD - usually with little or no violence. See Also: MOO , MUD |
| |
| NAMESERVER |
A computer running a program that converts domain names into appropriate IP addresses and vice versa. |
| |
| NAT |
NAT
(Network Address Translation) is the translation of an Internet
Protocol address (IP address) used within one network to a different IP
address known within another network. One network is designated the
inside network and the other is the outside. Typically, a company maps
its local inside network addresses to one or more global outside IP
addresses and unmaps the global IP addresses on incoming packets back
into local IP addresses. This helps ensure security since each outgoing
or incoming request must go through a translation process that also
offers the opportunity to qualify or authenticate the request or match
it to a previous request. NAT also conserves on the number of global IP
addresses that a company needs and it lets the company use a single IP
address in its communication with the world.
NAT is included as part of a router and is often part of a corporate
firewall. Network administrators create a NAT table that does the
global-to-local and local-to-global IP address mapping. NAT can also be
used in conjunction with policy routing. NAT can be statically defined
or it can be set up to dynamically translate from and to a pool of IP
addresses. Cisco's version of NAT lets an administrator create tables
that map:
A local IP address to one global IP address statically
A local IP address to any of a rotating pool of global IP addresses that a company may have
A local IP address plus a particular TCP port to a global IP address or one in a pool of them
A global IP address to any of a pool of local IP addresses on a round-robin basis
NAT is described in general terms in RFC 1631. which discusses NAT's
relationship to Classless Interdomain Routing (CIDR) as a way to reduce
the IP address depletion problem. NAT reduces the need for a large
amount of publicly known IP addresses by creating a separation between
publicly known and privately known IP addresses. CIDR aggregates
publicly known IP addresses into blocks so that fewer IP addresses are
wasted. In the end, both extend the use of IPv4 IP addresses for a few
more years before IPv6 is generally supported. |
| |
| NETIQUETTE |
Netiquette
is etiquette on the Internet. Since the Internet changes rapidly, its
netiquette does too, but its still usually based on the Golden Rule.
The need for a sense of netiquette arises mostly when sending or
distributing email, posting on Usenet groups, or chatting. To some
extent, the practice of netiquette depends on understanding how email,
the Usenet, chatting, or other aspects of the Internet actually work or
are practiced. So a little preliminary observation can help. Poor
netiquette because youre new is one thing, but such practices as spam
and flaming are another matter. |
| |
| NETIZEN |
The word netizen seems to have two similar meanings.
A citizen who uses the Internet as a way of participating in political
society (for example, exchanging views, providing information, and
voting).
An Internet user who is trying to contribute to the Internets use and
growth. As a powerful communications medium, the Internet seems to
offer great possibilities for social change. It also creates a new
culture and its own special issues, such as who shall have access to
it. The implication is that the Internets users, who use and know most
about it, have a responsibility to ensure that is used constructively
while also fostering free speech and open access. |
| |
| NETSCAPE |
Netscape
is one of the two most popular Web browsers and also the name of a
company, Netscape Communications, now owned by America Online (AOL).
Currently, almost all Internet users use either Netscapes browser or
Microsofts Internet Explorer (MSIE) browser, and many users use both.
Although Netscape was initially the predominant product in terms of
usability and number of users, Microsofts browser is now considered
superior by many users (although many other users see them as roughly
equivalent) and has taken a slight lead in usage.
Netscapes browser originally was called "Navigator," and is still
called that in the suite of software, Communicator, of which it is now
a part. Navigator was developed in 1995 by a team led by Marc
Andreessen, who created Mosaic, the first Web browser that had a
graphical user interface, at the University of Illinois National Center
for Supercomputing Applications (NCSA) in 1993.
The latest version of Netscape Navigator is 4.72 , now available in a
beta version. Navigator can be downloaded as part of the Communicator
suite from Netscapes Web site at no charge. CD-ROM versions can also be
purchased in computer stores and are sometimes distributed freely as
promotions.
A primary source of revenue for Netscape and AOL is the Netscape line
of Web server products that it develops and has marketed on the success
of its wide-scale browser usage. Netscape and AOL also envision the
Netscape Web site, now transformed into a leading Web portal, as a
leading source of revenue through advertising and e-commerce. |
| |
| NETWORK |
In
information technology, a network is a series of points or nodes
interconnected by communication paths. Networks can interconnect with
other networks and contain subnetworks.
The most common topologies or general configurations of networks
include the bus, star, and ring topologies. Networks can also be
characterized in terms of spatial distance as local area networks
(LANs), metropolitan area networks (MANs), and wide area networks
(WANs).
A given network can also be characterized by the type of data
transmission technology in use on it (for example, a TCP/IP or SNA
network); by whether it carries voice, data, or both kinds of signals;
by who can use the network (public or private); by the usual nature of
its connections (dial-up or switched, dedicated or non-switched, or
virtual connections); and by the types of physical links (for example,
optical fiber, coaxial cable, and copper wire). Large telephone
networks and networks using their infrastructure (such as the Internet)
have sharing and exchange arrangements with other companies so that
larger networks are created. |
| |
| NEWSGROUP |
A
newsgroup is a discussion about a particular subject consisting of
notes written to a central Internet site and redistributed through
Usenet, a worldwide network of news discussion groups. Usenet uses the
Network News Transfer Protocol (NNTP).
Newsgroups are organized into subject hierarchies, with the first few
letters of the newsgroup name indicating the major subject category and
sub-categories represented by a subtopic name. Many subjects have
multiple levels of subtopics. Some major subject categories are: news,
rec (recreation), soc (society), sci (science), comp (computers), and
so forth (there are many more). Users can post to existing newsgroups,
respond to previous posts, and create new newsgroups.
Newcomers to newsgroups are requested to learn basic Usenet
"netiquette" and to get familiar with a newsgroup before posting to it.
A FAQ is provided. The rules can be found when you start to enter the
Usenet through your browser or an online service. You can subscribe to
the postings on a particular newsgroup.
Some newsgroups are moderated by a designated person who decides which
postings to allow or to remove. Most newsgroups are immoderate.
|
| |
| NEWSREADER |
Program
that allows the user to read Newsgroup messages via Usenet, such as the
in built newsreaders in Internet Explorer or Netscape. There are also
dedicated newsreaders such as Forte Agent. |
| |
| NIC |
Networked
Information Center -- Generally, any office that handles information
for a network. The most famous of these on the Internet is the
InterNIC, which is where new domain names are registered.
Another
definition: (NIC) is a computer circuit board or card that is installed
in a computer so that it can be connected to a network. Personal
computers and workstations on local area networks (LANs) typically
contain a network interface card specifically designed for the LAN
transmission technology, such as Ethernet or Token Ring. Network
interface cards provide a dedicated, full-time connection to a network.
Most home and portable computers connect to the Internet through
as-needed dial-up connection. The modem provides the connection
interface to the Internet service provider. |
| |
| NNTP |
NNTP
(Network News Transfer Protocol) is the predominant protocol used by
computers (servers and clients) for managing the notes posted on Usenet
newsgroups. NNTP replaced the original Usenet protocol, UNIX-to-UNIX
Copy Protocol (UUCP) some time ago. NNTP servers manage the global
network of collected Usenet newsgroups and include the server at your
Internet access provider. An NNTP client is included as part of a
Netscape, Internet Explorer, Opera, or other Web browser or you may use
a separate client program called a newsreader. |
| |
| NODE |
In
a network, a node is a connection point, either a redistribution point
or an end point for data transmissions. In general, a node has
programmed or engineered capability to recognize and process or forward
transmissions to other nodes. |
| |
| OCR |
OCR
(optical character recognition) is the recognition of printed or
written text characters by a computer. This involves photo-scanning of
the text character-by-character, analysis of the scanned-in image, and
then translation of the character image into character codes, such as
ASCII, commonly used in data processing.
In OCR processing, the scanned-in image or bitmap is analysed for light
and dark areas in order to identify each alphabetic letter or numeric
digit. When a character is recognized, it is converted into an ASCII
code. Special circuit boards and computer chips designed expressly for
OCR are used to speed up the recognition process.
OCR is being used by libraries to digitize and preserve their holdings.
OCR is also used to process checks and credit card slips and sort the
mail. Billions of magazines and letters are sorted every day by OCR
machines, considerably speeding up mail delivery. |
| |
| OFFLINE |
When your computer performs an operation when it is not connected to any other computers or the Internet it is working offline. |
| |
| ONLINE |
Your computer is working online when it performs an operation and is connected to other computers or the Internet. |
| |
| OVERCLOCKING |
Overclocking
is resetting your computer so that the microprocessor runs faster than
the manufacturer-specified speed (for example, setting an Intel 166 MHz
(megahertz) microprocessor to run at 200 Mhz). Somewhat surprisingly,
this is possible. However, it's more likely to work with an Intel
microprocessor than with those of other manufacturers because,
according to Tom's Hardware Guide, Intel labels the speed of its
microprocessors more conservatively.
Factors that favor your ability to successfully "upgrade by resetting"
include (in addition to having an Intel microprocessor): having a
well-designed motherboard with a fast enough bus and having a fan or
other cooling device that will keep your system cool enough.
The procedure for "overclocking" depends on your combination of
factors. The first and most commonly applicable step is to reset your
computer's bus speed. The microprocessor is often able to adjust
successfully to a slightly higher bus speed. Resetting the bus speed
may require resetting jumpers inside your computer. In newer systems
with SoftMenu BIOS, the bus speed can be set through your system setup
interface. |
| |
| PABX |
A
PABX (private automatic branch exchange) is an automatic telephone
switching system within a private enterprise. Originally, such systems
- called private branch exchanges (PBXs) - required the use of a live
operator. Since almost all private branch exchanges today are
automatic, the abbreviation "PBX" usually implies a "PABX."
Some manufacturers of PABX (PBX) systems distinguish their products
from others by creating new kinds of private branch exchanges. Rolm
offers a Computerized Branch Exchange (CABX) and Usha Informatics
offers an Electronic Private Automatic Branch Exchange (EPABX). |
| |
| PACKET |
A
packet is the unit of data that is routed between an origin and a
destination on the Internet or any other packet-switched network. When
any file (email message, HTML file, GIF file, URL request, and so
forth) is sent from one place to another on the Internet, the
Transmission Control Protocol (TCP) layer of TCP/IP divides the file
into "chunks" of an efficient size for routing. Each of these packets
is separately numbered and includes the Internet address of the
destination. The individual packets for a given file may travel
different routes through the Internet. When they have all arrived, they
are reassembled into the original file (by the TCP layer at the
receiving end). |
| |
| PACKET SWITCHING |
A
packet-switching scheme is an efficient way to handle transmissions on
a connectionless network such as the Internet. An alternative scheme,
circuit-switching, is used for networks allocated for voice
connections. In circuit-switching, lines in the network are shared
among many users as with packet-switching, but each connection requires
the dedication of a particular path for the duration of the connection. |
| |
| PAGE |
1)
On the World Wide Web, a page is a file notated with the Hypertext
Markup Language (HTML). Usually, it contains text and specifications
about where image or other multimedia files are to be placed when the
page is displayed. You can think of a Web site as a book (albeit a
hypertext kind of book rather than a sequentially arranged kind of
book) that arrives a page at a time as you request each one. Each page
is an individual HTML file with its own Web address (URL). The first
page you usually request at a site is known as the home page. (Most
home pages have a default name that does not have to be specified; you
only need to enter the domain name for the site itself.) With frames,
multiple pages (HTML files) can be downloaded to a browser and
presented on designated sections of the display screen at the same
time.
2) In a computers random
access memory (RAM), a page is a group of memory cells that are
accessed as part of a single operation. That is, all the bits in the
group of cells are changed at the same time. In some kinds of RAM, a
page is all the memory cells in the same row of cells. In other kinds
of RAM, a page may represent some other group of cells than all those
in a row.
3) In computer systems that use virtual memory (also known as virtual
storage), a page is a unit of data storage that is brought into real
storage (on a personal computer, RAM) from auxiliary storage (on a
personal computer, usually the hard disk) when a requested item of data
is not already in real storage (RAM).
4) In printing, a page is what is printed on a single piece of paper.
|
| |
| PAP |
1)
PAP (Packet-Level Procedure) is a full-duplex protocol for transferring
packets between parties in an X.25 network. PAP supports data
sequencing, flow control, accountability, and error detection and
recovery.
2) PAP (Password
Authentication Procedure) is a procedure used by PPP servers to
validate a connection request. PAP works as follows:
After the link is established, the requestor sends a password and an id to the server.
The server either validates the request and sends back an
acknowledgement, terminates the connection, or offers the requestor
another chance.
Passwords are sent without security and the originator can make
repeated attempts to gain access. For these reasons, a server that
supports CHAP will offer to use that protocol before using PAP. PAP
protocol details can be found in RFC 1334.
|
| |
| PASSWORD |
A
password is an unspaced sequence of characters used to determine that a
computer user requesting access to a computer system is really that
particular user. Typically, users of a multiuser or securely protected
single-user system claim a unique name (often called a user ID) that
can be generally known. In order to verify that someone entering that
user ID really is that person, a second identification, the password,
known only to that person and to the system itself, is entered by the
user. A password is typically somewhere between five and 8 characters,
depending on how the computer system is set up. When a password is
entered, the computer system is careful not to display the characters
on the display screen, in case others might see it.
Good criteria when choosing a password or setting up password guidelines include the following:
Not a password that someone can easily guess if they know who you are
(for example, not your Social Security number, birthday, or maiden
name)
Not a word that can be found in the dictionary (since there are
programs that can rapidly try every word in the dictionary!)
Not a word that is currently newsworthy
Not a password that is similar to your previous password
A mixture of letters and at least one number
A word that you can easily remember
Many networks require that you change your password on some periodic basis.
|
| |
| PERL |
Perl
is a script programming language that is similar in syntax to the C
language and that includes a number of popular UNIX facilities such as
sed, awk, and tr. Perl is an interpreted language that can be compiled
just before execution into either C code or cross-platform byte-code.
When compiled, a Perl program is almost (but not quite) as fast as a
fully precompiled C language program. Perl is regarded as a good choice
for developing Common Gateway Interface (CGI) programs because it has
good text manipulation facilities (although it also handles binary
files). It was invented by Larry Wall.
In general, Perl is easier to learn and faster to code in than the more
structured C and C++ languages. Perl programs can, however, be quite
sophisticated. Perl tends to have devoted adherents.
Plug-ins can be installed for some servers (Apache, for example) so
that Perl is loaded permanently in memory, thus reducing compile time
and resulting in faster execution of CGI Perl scripts. |
| |
| PHP |
(Originally personal home page)
In Web programming, PHP is a script language and interpreter, similar
to JavaScript and Microsoft's VBScript, that is freely available and
used primarily on Linux Web servers. PHP (the initials come from the
earliest version of the program, which was called "Personal Home Page
Tools") is a cross-platform alternative to Microsoft's Active Server
Page (ASP) technology (which runs only on Microsoft's Windows NT
servers). As with ASP, the PHP script is embedded within a Web page
along with its HTML. Before the page is sent to a user that has
requested it, the Web server calls PHP to interpret and perform the
operations called for in the PHP script. An HTML page that includes a
PHP script is typically given a file name suffix of ".php" ".php3," or
".phtml". Like ASP, PHP can be thought of as "dynamic HTML pages,"
since content will vary based on the results of interpreting the script. |
| |
| PHTML |
A
PHTML (or its sometimes called a PHP) page is a Web page that includes
a script written in PHP, a language comparable to JavaScript or
Microsofts VBScript. Like Microsofts Active Server Page (ASP) page, a
PHTML page contains programming that is executed at the Web server
rather than at the Web client (which is usually your Web browser). You
may sometimes see a Web site whose address or URL ends with a file with
a suffix of ".phtml"" or ".php3". Either of these suffixes indicate an
HTML page that includes a PHP script. |
| |
| PING |
Ping
is a basic Internet program that lets you verify that a particular
Internet address exists and can accept requests. The verb ping means
the act of using the ping utility or command. Ping is used
diagnostically to ensure that a host computer you are trying to reach
is actually operating. If, for example, a user can |
| |
| PKZIP OR PKUNUZIP |
Utilities for easily compressing and uncompressing DOS and Windows files. They use the .zip filename extension. |
| |
| PLUG-IN |
Plug-in
applications are programs that can easily be installed and used as part
of your Web browser. Initially, the Netscape browser allowed you to
download, install, and define supplementary programs that played sound
or motion video or performed other functions. These were called helper
applications. However, these applications run as a separate application
and require that a second window be opened. A plug-in application is
recognised automatically by the browser and its function is integrated
into the main HTML file that is being presented.
Among popular plug-ins to download are Adobes Acrobat, a document
presentation and navigation program that lets you view documents just
as they look in the print medium, RealNetworks streaming media player,
and Macromedias Shockwave for DIrector, an interactive animation and
sound player. There are now hundreds of possible plug-ins. Most users
wait until they need a particular plug-in before they download it.
|
| |
| POP |
Point
of Presence, also Post Office Protocol -- Two commonly used meanings:
Point of Presence and Post Office Protocol. A Point of Presence usually
means a city or location where a network can be connected to, often
with dial up phone lines. So if an Internet company says they will soon
have a POP in Belgrade, it means that they will soon have a local phone
number in Belgrade and/or a place where leased lines can connect to
their network. A second meaning.
Post Office Protocol refers to the way email software such as Eudora
gets mail from a mail server. When you obtain a SLIP, PPP, or shell
account you almost always get a POP account with it, and it is this POP
account that you tell your email software to use to get your mail. |
| |
| POP3 |
POP3
(Post Office Protocol 3) is the most recent version of a standard
protocol for receiving email. POP3 is a client/server protocol in which
email is received and held for you by your Internet server.
Periodically, you (or your client email receiver) check your mail-box
on the server and download any mail. POP3 is built into the Netmanage
suite of Internet products and one of the most popular email products,
Eudora. It's also built into the Netscape and Microsoft Internet
Explorer browsers.
An
alternative protocol is IMAP (Interactive Mail Access Protocol). With
IMAP, you view your email at the server as though it was on your client
computer. An email message deleted locally is still on the server.
Email can be kept on and searched at the server.
POP can be thought of as a "store-and-forward" service. IMAP can be thought of as a remote file server.
POP and IMAP deal with the receiving of email and are not to be
confused with the Simple Mail Transfer Protocol (SMTP), a protocol for
transferring email across the Internet. You send email with SMTP and a
mail handler receives it on your recipient's behalf. Then the mail is
read using POP or IMAP. |
| |
| PORT |
1)
On computer and telecommunication devices, a port (noun) is generally a
specific place for being physically connected to some other device,
usually with a socket and plug of some kind. Typically, a personal
computer is provided with one or more serial ports and usually one
parallel port. The serial port supports sequential, one bit-at-a-time
transmission to peripheral devices such as scanners and the parallel
port supports multiple-bit-at-a-time transmission to devices such as
printers.
2) In programming, a
port (noun) is a "logical connection place" and specifically, using the
Internets protocol, TCP/IP, the way a client program specifies a
particular server program on a computer in a network. Higher-level
applications that use TCP/IP such as the Web protocol, HTTP, have ports
with preassigned numbers. These are known as "well-known ports" that
have been assigned by the Internet Assigned Numbers Authority (IANA).
Other application processes are given port numbers dynamically for each
connection. When a service (server program) initially is started, it is
said to bind to its designated port number. As any client program wants
to use that server, it also must request to bind to the designated port
number.
3) In programming, to port (verb) is to move an application program
from an operating system environment in which it was developed to
another operating system environment so it can be run there. Porting
implies some work, but not nearly as much as redeveloping the program
in the new environment. Open standard programming interfaces (such as
those specified in X/Opens UNIX 95 C language specification and Sun
Microsystems Java programming language) minimize or eliminate the work
required to port a program. |
| |
| PORTAL |
1)
Portal is a new term, generally synonymous with gateway, for a World
Wide Web site that is or proposes to be a major starting site for users
when they get connected to the Web or that users tend to visit as an
anchor site. There are general portals and specialized or niche
portals. Some major general portals include Yahoo, Excite, Netscape,
Lycos, CNET, Microsoft Network, and America Onlines AOL.com. Examples
of niche portals include Garden.com (for gardeners), Fool.com (for
investors), and SearchNT.com (for Windows NT administrators).
A number of large access providers offer portals to the Web for their
own users. Most portals have adopted the Yahoo style of content
categories with a text-intensive, faster loading page that visitors
will find easy to use and to return to. Companies with portal sites
have attracted much stock market investor interest because portals are
viewed as able to command large audiences and numbers of advertising
viewers.
Typical services offered by portal sites include a directory of Web
sites, a facility to search for other sites, news, weather information,
email, stock quotes, phone and map information, and sometimes a Market
Place forum. Excite is among the first portals to offer users the
ability to create a site that is personalized for individual interests.
The term portal space is used to mean the total number of major sites competing to be one of the portals.
2) In fantasy games, science-fiction, and some "New Age" philosophies,
a portal is a gateway to another world of the past, present, or future,
or to an expanded awareness.
3) In 3-D graphics development, portal rendering is a technique that
increases the effect of realism and speeds up presentation. |
| |
| POSTING |
A single message entered into a network communications system.
E.g. A single message posted to a newsgroup or message board. |
| |
| POTS |
POTS
is a term sometimes used in discussion of new telephone technologies in
which the question of whether and how existing voice transmission for
ordinary phone communication can be accommodated. For example, ADSL and
ISDN provide some part of their channels for "plain old telephone
service" while providing most of their bandwidth for digital data
transmission. |
| |
| PPP |
PPP
(Point-to-Point Protocol) is a protocol for communication between two
computers using a serial interface, typically a personal computer
connected by phone line to a server. For example, your Internet server
provider may provide you with a PPP connection so that the providers
server can respond to your requests, pass them on to the Internet, and
forward your requested Internet responses back to you. PPP uses the
Internet protocol (IP) (and is designed to handle others). It is
sometimes considered a member of the TCP/IP suite of protocols.
Relative to the Open Systems Interconnection (OSI) reference model, PPP
provides layer 2 (data-link layer) service. Essentially, it packages
your computers TCP/IP packets and forwards them to the server where
they can actually be put on the Internet.
PPP is a full-duplex protocol that can be used on various physical
media, including twisted pair or fiber optic lines or satellite
transmission. It uses a variation of High Speed Data Link Control
(HDLC) for packet encapsulation.
PPP is usually preferred over the earlier de facto standard Serial Line
Internet Protocol (SLIP) because it can handle synchronous as well as
asynchronous communication. PPP can share a line with other users and
it has error detection that SLIP lacks. Where a choice is possible, PPP
is preferred.
|
| |
| PSTN |
The
PSTN (public switched telephone network) refers to the worlds
collection of interconnected voice-oriented public telephone networks,
both commercial and government-owned. Its also referred to as the Plain
Old Telephone Service (POTS). Its the aggregation of circuit-switching
telephone networks that has evolved from the days of Alexander Graham
Bell ("Doctor Watson, come here!"). Today, it is almost entirely
digital in technology except for the final link from the central
(local) telephone office to the user.
In relation to the Internet, the PSTN actually furnishes much of the
Internets long-distance infrastructure. Because Internet service
providers ISPs pay the long-distance providers for access to their
infrastructure and share the circuits among many users through
packet-switching, Internet users avoid having to pay usage tolls to
anyone other than their ISPs.
|
| |
| PUBLIC ACCESS PROVIDER |
An organization that provides Internet access for individuals or other organizations, often for a fee. |
| |
| PUBLIC DOMAIN |
Programs
that are open to copy because their authors intended to share them with
everyone else are in the public domain. The UNIX community has
developed a number of such programs over the years. Programs in the
public domain can be used without restriction as components of other
programs. When reusing such code, it is good to understand its history
so that you can be sure it really is in the public domain. |
| |
| QWERTY |
The
QWERTY (pronounced KWEHR-tee) keyboard is the standard typewriter and
computer keyboard in countries that use a Latin-based alphabet. QWERTY
refers to the first six letters on the upper row of the keyboard. The
key arrangement was devised by Christopher Latham Sholes whose
"Type-Writer," as it was then called, was first mass-produced in 1874.
Since that time, it has become what may be the most ubiquitous
machine-user interface of all time.
The QWERTY arrangement was intended to reduce the jamming of typebars
as they moved to strike ink on paper. Separating certain letters from
each other on the keyboard reduced the amount of jamming. In 1932,
August Dvorak developed what was intended to be a faster keyboard,
putting the vowels and the five most common consonants in the middle
row, with the idea that an alternating rhythm would be established
between left and right hands. Although the Dvorak keyboard has many
adherents, it has never overcome the culture of learning to type on a
QWERTY. |
| |
| RADIUS |
RADIUS
(Remote Authentication Dial-In User Service) is a client/server
protocol and software that enables remote access servers to communicate
with a central server to authenticate dial-in users and authorize their
access to the requested system or service. RADIUS allows a company to
maintain user profiles in a central database that all remote servers
can share. It provides better security, allowing a company to set up a
policy that can be applied at a single administered network point.
Having a central service also means that it's easier to track usage for
billing and for keeping network statistics. Created by Livingston (now
owned by Lucent), RADIUS is a de facto industry standard used by Ascend
and other network product companies and is a proposed IETF standard. |
| |
| REGISTRY |
1)
In the Microsoft Windows 95, Windows 98, and Windows NT operating
systems, the Registry is a single place for keeping such information as
what hardware is attached, what system options have been selected, how
computer memory is set up, and what application programs are to be
present when the operating system is started. The Registry is somewhat
similar to and a replacement for the simpler INI (initialization) and
configuration files used in earlier Windows systems. INI files are
still supported, however, for compatibility with the 16-bit
applications written for earlier systems.
In general, the user updates the Registry indirectly using Control
Panel tools, such as Tweak UI. When you install or uninstall
application programs, they also update the Registry. In a network
environment, Registry information can be kept on a server so that
system policies for individuals and workgroups can be managed
centrally.
2) The Internet Registry manages the Internet's domain name system. It
is supervised by the Internet Architecture Board of the Internet
Society. |
| |
| RENDERING |
To
render (a verb, pronounced REHN-dir, from the medieval French rendre
meaning "to give back or yield") has a number of usages along the lines
of forming something out of something else originally given. A jury
renders a verdict given evidence and the rules of law. Animal fat can
be rendered into lard. Out of loyalty to the king, a service is
rendered. An artist can render an idea in the mind into a drawing on
paper. A translator renders one language into another.
In computer graphics technology, computer software can be used to
render special 3-D effects given the right programming statements. A
computer display system renders an image that is sent to it in the form
of a bitmap or streaming image.
A rendering (noun) is a term sometimes used to describe a drawing,
sketch, plan, or other artistic or engineered effort to depict or
portray something on paper or in another medium. |
| |
| ROTFL |
Abbreviation of roll on the floor laughing, commonly used online or on IRC. |
| |
| ROUTER |
On
the Internet, a router is a device or, in some cases, software in a
computer, that determines the next network point to which a packet
should be forwarded toward its destination. The router is connected to
at least two networks and decides which way to send each information
packet based on its current understanding of the state of the networks
it is connected to. A router is located at any juncture of networks or
gateway, including each Internet point-of-presence. A router is often
included as part of a network switch.
A router creates or maintains a table of the available routes and their
conditions and uses this information along with distance and cost
algorithms to determine the best route for a given packet. Typically, a
packet may travel through a number of network points with routers
before arriving at its destination. An edge router is a router that
interfaces with an asynchronous transfer mode (ATM) network. A brouter
is a network bridge combined with a router. |
| |
| RTS |
Request To Send. |
| |
| SCRIPTING LANGUAGE |
Series of programmed commands that designate how one computer communicates with another computer. |
| |
| SEARCH ENGINE |
On the Internet, a search engine has three parts:
A spider (also called a "crawler" or a "bot") that goes to every page
or representative pages on every Web site that wants to be searchable
and reads it, using hypertext links on each page to discover and read a
site's other pages
A program that creates a huge index (sometimes called a "catalog") from the pages that have been read
A program that receives your search request, compares it to the entries in the index, and returns results to you
An alternative to using a search engine is to explore a structured
directory of topics. Yahoo, which also lets you use its search engine,
is the most widely-used directory on the Web. A number of Web portal
sites offer both the search engine and directory approaches to finding
information.
Different Search Engine Approaches
Major search engines such as Yahoo, AltaVista, Lycos, and Google index
the content of a large portion of the Web and provide results that can
run for pages - and consequently overwhelm the user.
Specialized content search engines are selective about what part of the
Web is crawled and indexed. For example, TechTarget sites for products
such as the AS/400 (http://www.search400.com) and Windows NT
(http://www.searchnt.com) selectively index only the best sites about
these products and provide a shorter but more focused list of results.
Ask Jeeves (http://www.askjeeves.com) provides a general search of the
Web but allows you to enter a search request in natural language, such
as "What's the weather in Seattle today?"
Special tools such as WebFerret (from http://www.softferret.com) let
you use a number of search engines at the same time and compile results
for you in a single list.
Individual Web sites, especially larger corporate sites, may use a
search engine to index and retrieve the content of just their own site.
Some of the major search engine companies license or sell their search
engines for use on individual sites.
Where to Search First
The last time we looked, the Open Directory Project listed 370 search
engines available for Internet users. There are about ten major search
engines, each with its own anchor Web site (although some have an
arrangement to use another site's search engine or license their own
search engine for use by other Web sites). Some sites, such as Yahoo,
search not only using their search engine but also give you the results
from simultaneous searches of other search indexes. Sites that let you
search multiple indexes simultaneously include:
Yahoo (http://www.yahoo.com)
search.com (http://search.com)
EasySearcher (http://www.easysearcher.com)
Yahoo first searches its own hierarchically-structured subject
directory and gives you those entries. Then, it provides a few entries
from the AltaVista search engine. It also launches a concurrent search
for entries matching your search argument with six or seven other major
search engines. You can link to each of them from Yahoo (at the bottom
of the search result page) to see what the results were from each of
these search engines. |
| |
| SECURITY CERTIFICATE |
A chunk of information (often stored as a text file) that is used by the SSL protocol to establish a secure connection.
Security Certificates contain information about who it belongs to, who
it was issued by, a unique serial number or other unique
identification, valid dates, and an encrypted “fingerprint” that can be
used to verify the contents of the certificate.
In order for an SSL connection to be created both sides must have a valid Security Certificate |
| |
| SELF EXTRACTING ARCHIVE |
An
archived file with the filename extension .exe, indicating that when
downloaded and run, it will be extracted by the decompressing program
around it, without user intervention, or the need to have additional
decompression software. |
| |
| SERVER |
1) In general, a server is a computer program that provides services to other computer programs in the same or other computers.
2) The computer that a server program runs in is also frequently
referred to as a server (though it may contain a number of server and
client programs).
3) In the client/server programming model, a server is a program that
awaits and fulfils requests from client programs in the same or other
computers. A given application in a computer may function as a client
with requests for services from other programs and a server of requests
from other programs.
Specific to the Web, a Web server is the computer program (housed in a
computer) that serves requested HTML pages or files. A Web client is
the requesting program associated with the user. The Web browser in
your computer is a client that requests HTML files from Web servers. |
| |
| SGML |
SGML
(Standard Generalized Markup Language) is a standard for how to specify
a document markup language or tag set. Such a specification is itself a
document type definition (DTD). SGML is not in itself a document
language, but a description of how to specify one. It is a
metalanguage.
SGML is based on
the idea that documents have structural and other semantic elements
that can be described without reference to how such elements should be
displayed. The actual display of such a document may vary, depending on
the output medium and style preferences. Some advantages of documents
based on SGML are:
They can be created by thinking in terms of document structure rather
than appearance characteristics (which may change over time).
They will be more portable because an SGML compiler can interpret any
document by reference to its document tag definition (DTD).
Documents originally intended for the print medium can easily be
re-adapted for other media, such as the computer display screen.
The language that this Web browser uses, Hypertext Markup Language
(HTML), is an example of an SGML-based language. There is a document
type definition for HTML (and reading the HTML specification is
effectively reading an expanded version of the document type
definition).
SGML is based somewhat on earlier generalized markup languages
developed at IBM, including General Markup Language (GML) and ISIL. |
| |
| SHAREWARE |
Shareware
is software that is distributed free on a trial basis with the
understanding that the user may need or want to pay for it later. Some
software developers offer a shareware version of their program with a
built-in expiration date (after 30 days, the user can no longer get
access to the program). Other shareware (sometimes called liteware) is
offered with certain capabilities disabled as an enticement to buy the
complete version of the program.
Freeware is programming that is offered at no cost. However, it is
copyrighted so that you cant incorporate its programming into anything
you may be developing. The least restrictive "no-cost" programs are
open to copy programs in the public domain. These include a number of
small UNIX programs. When reusing public domain software in your own
programs, its good to know the history of the program so that you can
be sure it really is in the public domain.
|
| |
| SIGNATURE |
The
automatic addition of a few lines at the foot of an Email. These
usually consist of the sender's Email address, full name and other
details. |
| |
| SLIP |
SLIP
is a TCP/IP protocol used for communication between two machines that
are previously configured for communication with each other. For
example, your Internet server provider may provide you with a SLIP
connection so that the providers server can respond to your requests,
pass them on to the Internet, and forward your requested Internet
responses back to you. Your dial-up connection to the server is
typically on a slower serial line rather than on the parallel or
multiplex lines such as a T-1 line of the network you are hooking up
to.
A better service is provided by the Point-to-Point Protocol (PPP).
|
| |
| SMDS |
SMDS
(Switched Multimegabit Data Service) is a public, packet-switched
service aimed at enterprises that need to exchange large amounts of
data with other enterprises over the wide-area network on a nonconstant
or "bursty" basis. SMDS provides an architecture for this kind of data
exchange and a set of services. In general, SMDS extends the
performance and efficiencies of a companys local area network (LANs)
over a wide area on a switched, as-needed basis.
SMDS is
connectionless, meaning that there is no need to set up a connection
through the network before sending data. This provides bandwidth on
demand for the "bursty" data transmission typically found on LANs.
SMDS packets contain up to 7168 bytes of data, which is large enough to
accept the most common LAN packets. Each packet includes the source
address and the destination address and is sent separately from other
packets.
Each enterprise using SMDS is assigned from one to sixteen unique SMDS
addresses, depending on needs. An address is a ten digit number that
looks like an ordinary telephone number.
SMDS also provides for broadcasting packets to multiple SMDS addresses.
Each SMDS company is assigned one or more group addresses that can be
used to define destination groups. Group addressing is similar to LAN
multicasting. It lets routing protocols, such as TCP/IP, use dynamic
address resolution and routing updates.
Since SMDS is a public service, any SMDS customer can exchange data
with any other customer. The SMDS Interest Group, an association of
service providers, equipment manufacturers, and users, develops
technical specifications, promotes awareness of SMDS, stimulates new
applications, and ensures worldwide service interoperability, working
with its international affiliates. Their home page provides a list of
companies providing SMDS services. |
| |
| SME |
Small-to-medium
enterprise is a convenient term for segmenting businesses and other
organizations that are somewhere between the "small office-home office"
(SOHO) size and the larger enterprise. The European Union has defined
an SME as a legally independent company with no more than 500 employees. |
| |
| SMILEYS |
Characters
often used in News messages, Emails and on Web Pages to offer some
degree of character or emotion. Example :-) or >:(
Here is a larger list...
:-) Your basic smiley. This smiley is used to inflect a sarcastic or joking
statement since we can't hear voice inflection over email.
;-) Winky smiley. User just made a flirtatious and or sarcastic remark. More
of a "don't hit me for what I just said" smiley.
:-( Frowning smiley. User did not like that last statement or is upset or
depressed about something.
:-I Indifferent smiley. Better than a :-( but not quite as good as a :-).
:-> User just made a really biting sarcastic remark. Worse than a ;-).
>:-> User just made a really devilish remark.
>;-> Winky and devil combined. A very lewd remark was just made. |
| |
| SMS |
SMS
(Short Message Service) is a service for sending messages of up to 160
characters to mobile phones that use Global System for Mobile (GSM)
communication. GSM and SMS service is primarily available in Europe.
SMS is similar to paging. However, SMS messages do not require the
mobile phone to be active and within range and will be held for a
number of days until the phone is active and within range. SMS messages
are transmitted within the same cell or to anyone with roaming
capability. They can also be sent to digital phones from a Web site
equipped with PC Link or from one digital phone to another. Typical
uses of SMS include:
Notifying a mobile phone owner of a voicemail message
Notifying a salesperson of an inquiry and contact to call
Notifying a doctor of a patient with an emergency problem
Notifying a service person of the time and place of their next call
Notifying a driver of the address of the next pickup
An SMS gateway is a Web site that lets you enter an SMS message to
someone within the cell served by that gateway or that acts as an
international gateway for users with roaming capability. |
| |
| SMTP |
SMTP
(Simple Mail Transfer Protocol) is a TCP/IP protocol used in sending
and receiving email. However, since its limited in its ability to queue
messages at the receiving end, its usually used with one of two other
protocols, POP3 or IMAP, that let the user save messages in a server
mailbox and download them periodically from the server. In other words,
users typically use a program that uses SMTP for sending email and
either POP3 or IMAP for receiving messages that have been received for
them at their local server. Most mail programs such as Eudora let you
specify both an SMTP server and a POP server. On UNIX-based systems,
sendmail is the most widely-used SMTP server for email. A commercial
package, Sendmail, includes a POP3 server and also comes in a version
for Windows NT.
SMTP usually is
implemented to operate over TCP port 25. The details of SMTP are in RFC
821 of the Internet Engineering Task Force (IETF). An alternative to
SMTP that is widely used in Europe is X.400. |
| |
| SNAIL MAIL |
Snail
mail is a slang term for the regular postal service (for example, the
Royal Mail) with the implication that it is a lot slower than email.
Its worth noting, perhaps, that in the early days of the Internet, it
was proposed that the (then) U. S. Post Office manage email. Electronic
messages would come to your local post office and then be delivered to
you along with the regular mail. The proposal was not considered for
very long.
Snail mail or not,
one must acknowledge that regular postal services offer a number of
valuable services not likely to be available soon on the World Wide
Web.
Write a letter. Buy a stamp, put stamp on letter. Walk to the postbox
and post letter. Wait a day or two and hopefully it will have reached
its intended destination...thats s n a i l - m a i l. |
| |
| SNMP |
Simple
Network Management Protocol -- A set of standards for communication
with devices connected to a TCP/IP network. Examples of these devices
include routers, hubs, and switches.
A device is said to be “SNMP compatible” if it can be monitored and/or
controlled using SNMP messages. SNMP messages are known as “PDU's” -
Protocol Data Units.
Devices that are SNMP compatible contain SNMP “agent” software to receive, send, and act upon SNMP messages.
Software for managing devices via SNMP are available for every kind of
commonly used computer and are often bundled along with the device they
are designed to manage. Some SNMP software is designed to handle a wide
variety of devices.
|
| |
| SPAM (SPAMMING) |
Spam
is unsolicited email on the Internet. From the senders point-of-view,
its a form of bulk mail, often to a list culled from subscribers to a
Usenet discussion group or obtained by companies that specialize in
creating email distribution lists. To the receiver, it usually seems
like junk email. In general, its not considered good netiquette to send
spam. Its generally equivalent to unsolicited phone marketing calls
except that the user pays for part of the message since everyone shares
the cost of maintaining the Internet.
Some apparently unsolicited email is, in fact, email people agreed to
receive when they registered with a site and checked a box agreeing to
receive postings about particular products or interests. Its also
possible that some spam occasionally does find a welcome audience.
A first-hand report indicates that the term is derived from a famous
Monty Python sketch ("Well, we have Spam, tomato & Spam, egg &
Spam, Egg, bacon & Spam...") that was current when spam first began
arriving on the Internet. Spam is a trademarked Hormel meat product
that was well-known in the U.S. Armed Forces during World War II. |
| |
| SPIDER |
A
spider is a program that visits Web sites and reads their pages and
other information in order to create entries for a search engine index.
The major search engines on the Web all have such a program, which is
also known as a "crawler" or a "bot." Spiders are typically programmed
to visit sites that have been submitted by their owners as new or
updated. Entire sites or specific pages can be selectively visited and
indexed. Spiders are called spiders because they usually visit many
sites in parallel at the same time, their "legs" spanning a large area
of the "web." Spiders can crawl through a site's pages in several ways.
One way is to follow all the hypertext links in each page until all the
pages have been read.
The
spider for the AltaVista search engine and its Web site is called
Scooter. Scooter adheres to the rules of politeness for Web spiders
that are specified in the Standard for Robot Exclusion (SRE). It asks
each server which files should be excluded from being indexed. It does
not (or can not) go through firewalls. And it uses a special algorithm
for waiting between successive server requests so that it doesn't
affect response time for other users. |
| |
| SQL |
SQL
(Structured Query Language) is a standard interactive and programming
language for getting information from and updating a database. Although
SQL is both an ANSI and an ISO standard, many database products support
SQL with proprietary extensions to the standard language. Queries take
the form of a command language that lets you select, insert, update,
find out the location of data, and so forth. There is also a
programming interface. |
| |
| SSL |
SSL
(Secure Sockets Layer) is a program layer created by Netscape for
managing the security of message transmissions in a network. Netscapes
idea is that the programming for keeping your messages confidential
ought to be contained in a program layer between an application (such
as your Web browser or HTTP) and the Internets TCP/IP layers. The
"sockets" part of the term refers to the sockets method of passing data
back and forth between a client and a server program in a network or
between program layers in the same computer. Netscapes SSL uses the
public-and-private key encryption system from RSA, which also includes
the use of a digital certificate.
SSL is an integral part of each Netscape browser. If a Web site is on a
Netscape server, SSL can be enabled and specific Web pages can be
identified as requiring SSL access. Other servers can be enabled by
using Netscapes SSLRef program library which can be downloaded for
non-commercial use or licensed for commercial use.
Netscape has offered SSL as a proposed standard protocol to the World
Wide Web Consortium (W3C) and the Internet Engineering Task Force
(IETF) as a standard security approach for Web browsers and servers. |
| |
| Static IP |
Each
computer on the Internet has an address, an example of such is
194.69.121.3 The IP address distinguishes between each and every
computer on the Internet. This IP address usually changes every time
you make an Internet connection, so if you come offline and then
connect a little later your IP address will have changed.
You
would need a Static IP Address if you wish to turn your computer into
some sort of server. If you have decided to store downloadable
documents or software on your server a Static IP is the solution. |
| |
| SUBSCRIBE |
To become of a member of. One can subscribe to a mailing list, a newsgroup, an online service or an Internet Service. |
| |
| SURFING |
To
surf the Internet is to explore cyberspace without a predefined agenda.
By cyberspace, we generally mean the World Wide Web. Prior to 1997,
many people surfed gopherspace and some also surfed "FTP-space."
Note that Web users often find themselves surfing after starting out
with a specific Web site to visit. The Web is like that because it is a
web of interconnections whose relevance and attraction for any given
Web user are impossible to predict in advance. |
| |
| SWITCH |
In
telecommunications, a switch is a network device that selects a path or
circuit for sending a unit of data to its next destination. A switch
may also include the function of the router, a device or program that
can determine the route and specifically what adjacent network point
the data should be sent to. In general, a switch is a simpler and
faster mechanism than a router, which requires knowledge about the
network and how to determine the route.
On larger networks, the trip from one switch point to another in the
network is called a hop. The time a switch takes to figure out where to
forward a data unit is called its latency. The price paid for having
the flexibility that switches provide in a network is this latency.
Switches are found at the backbone and gateway levels of a network
where one network connects with another and at the subnetwork level
where data is being forwarded close to its destination or origin.
A switch is not always required in a network. Many local area networks
(LANs) are organized as rings or buses in which all destinations
inspect each message and read only those intended for that destination. |
| |
| SYSOP |
A
sysop is the person who runs a computer server. The term is used mainly
in the world of bulletin board services (BBSs) . In general, a sysop or
system operator is one who runs the day-to-day operation of a server
and the term suggests a person who is available when the system is. A
related term is administrator. In larger computer systems, the
administrator manages security and user access while a system operator
monitors and performs routine operations at the computer. In smaller
computer systems (for example, UNIX systems), the administrator and the
system operator tend to be the same person. |
| |
| T-1 |
The
T-carrier system, introduced by the Bell System in the U.S. in the
1960s, was the first successful system that supported digitised voice
transmission. The original transmission rate (1.544 Mbps) in the T-1
line is in common use today in Internet service provider (ISP)
connections to the Internet. Another level, the T-3 line, providing
44.736 Mbps, is also commonly used by ISPs. Another commonly installed
service is a fractional T-1 line, which is the rental of some portion
of the 24 channels in a T-1 line, with the other channels going unused.
The T-carrier system is entirely
digital, using pulse code modulation and time-division multiplexing.
The system uses four wires and provides full-duplex capability (two
wires for receiving and two for sending at the same time). The T-1
digital stream consists of 24 64-Kbps channels that are multiplexed.
(The standardized 64 Kbps channel is based on the bandwidth required
for a voice conversation.) The four wires were originally a pair of
twisted-pair copper wires, but can now also include coaxial cable,
optical fiber, digital microwave, and other media. A number of
variations on the number and use of channels are possible.
In the T-1 system, voice signals are sampled 8,000 times a second and
each sample is digitised into an 8-bit word. With 24 channels being
digitised at the same time, a 192-bit frame (24 channels each with an
8-bit word) is thus being transmitted 8,000 times a second. Each frame
is separated from the next by a single bit, making a 193-bit block. The
192 bit frame multiplied by 8,000 and the additional 8,000 framing bits
make up the T-1s 1.544 Mbps data rate. The signalling bits are the
least significant bits per frame.
|
| |
| T-3 |
A
leased-line connection capable of carrying data at 44,736,000
bits-per-second. This is more than enough to do full-screen,
full-motion video. |
| |
| TA |
A
terminal adapter (TA) is a hardware interface between a computer and an
ISDN line. It's what replaces a modem when you are using an ISDN
connection. Unlike "plain old telephone service," which carries signals
in analog (voice) form between your computer and the telephone
company's office, ISDN carries signals in digital form so there is no
need to modulate and demodulate between analog and digital signals. The
terminal adapter is what you have to install on a computer so that data
can be fed directly into the ISDN line in digital form. Since ISDN
service is not available from telephone companies in all areas, the
terminal adapter is not usually built into a computer. You purchase and
install it when you sign up for ISDN service. |
| |
| TAG |
A
tag is a generic term for a language element descriptor. The set of
tags for a document or other unit of information is sometimes referred
to as markup, a term that dates to pre-computer days when writers and
copy editors marked up document elements with copy editing symbols or
shorthand. |
| |
| TCP/IP |
TCP/IP
(Transmission Control Protocol/Internet Protocol) is the basic
communication language or protocol of the Internet. It can also be used
as a communications protocol in the private networks called intranets
and in extranets. When you are set up with direct access to the
Internet, your computer is provided with a copy of the TCP/IP program
just as every other computer that you may send messages to or get
information from also has a copy of TCP/IP.
TCP/IP is a two-layered program. The higher layer, Transmission Control
Protocol, manages the assembling of a message or file into smaller
packets that are transmitted over the Internet and received by a TCP
layer that reassembles the packets into the original message. The lower
layer, Internet Protocol, handles the address part of each packet so
that it gets to the right destination. Each gateway computer on the
network checks this address to see where to forward the message. Even
though some packets from the same message are routed differently than
others, theyll be reassembled at the destination.
TCP/IP uses the client/server model of communication in which a
computer user (a client) requests and is provided a service (such as
sending a Web page) by another computer (a server) in the network.
TCP/IP communication is primarily point-to-point, meaning each
communication is from one point (or host computer) in the network to
another point or host computer. TCP/IP and the higher-level
applications that use it are collectively said to be "stateless"
because each client request is considered a new request unrelated to
any previous one (unlike ordinary phone conversations that require a
dedicated connection for the call duration). Being stateless frees
network paths so that everyone can use them continuously. (Note that
the TCP layer itself is not stateless as far as any one message is
concerned. Its connection remains in place until all packets in a
message have been received.)
Many Internet users are familiar with the even higher layer application
protocols that use TCP/IP to get to the Internet. These include the
World Wide Webs Hypertext Transfer Protocol (HTTP), the File Transfer
Protocol (FTP), Telnet (Telnet) which lets you logon to remote
computers, and the Simple Mail Transfer Protocol (SMTP). These and
other protocols are often packaged together with TCP/IP as a "suite."
Personal computer users usually get to the Internet through the Serial
Line Internet Protocol (SLIP) or the Point-to-Point Protocol (PPP).
These protocols encapsulate the IP packets so that they can be sent
over a dial-up phone connection to an access providers modem.
Protocols related to TCP/IP include the User Datagram Protocol (UDP),
which is used instead of TCP for special purposes. Other protocols are
used by network host computers for exchanging router information. These
include the Internet Control Message Protocol (ICMP), the Interior
Gateway Protocol (IGP), the Exterior Gateway Protocol (EGP), and the
Border Gateway Protocol (BGP). |
| |
| TELCO |
In
the United States and possibly other countries, "telco" is a short form
for telephone company. Sometimes it means a local telephone company,
such as a Bell operating company (BOC) or an independent local
telephone company. Sometimes it means any telephone company, including
one offering long-distance services. |
| |
| TELNET |
Telnet
is the way you can access someone elses computer, assuming they have
given you permission. (Such a computer is frequently called a host
computer.) More technically, Telnet is a user command and an underlying
TCP/IP protocol for accessing remote computers. The Web or HTTP
protocol and the FTP protocol allow you to request specific files from
remote computers, but not to actually be logged on as a user of that
computer. With Telnet, you log on as a regular user with whatever
privileges you may have been granted to the specific applications and
data on that computer.
A Telnet command request looks like this (the computer name is made-up):
telnet mail.breathepro.com 110
The result of this request would be an invitation to log on with a
userid and a prompt for a password. If accepted, you would be logged
on.
Telnet is most likely to be used by program developers and anyone who
has a need to use specific applications or data located at a particular
host computer.
|
| |
| TERABYTE |
A
terabyte is a measure of computer storage capacity and is 2 to the 40th
power or, in decimal, approximately a thousand billion bytes (that is,
a thousand gigabytes). |
| |
| TERMINAL |
1)
In data communications, a terminal is any device that terminates one
end (sender or receiver) of a communicated signal. In practice, it is
usually applied only to the extended end points in a network, not
central or intermediate devices. In this usage, if you can send signals
to it, its a terminal.
2) In
telephony, the term Data Terminal Equipment (DTE) is used to describe
the computer end of the DTE-to-DCE (Data Communications Equipment)
communication between a computer and a modem.
3) In computers, a terminal (sometimes qualified as a "dumb" terminal)
is an end-use device (usually with display monitor and keyboard) with
little or no software of its own that relies on a mainframe or another
computer (such as a PC server) for its "intelligence." IBMs 3270
Information Display System was a widely-installed system of such
terminals in corporations. Many applications designed for the 3270 or
other "dumb" terminals are still in use at PCs that emulate or act like
a 3270. The VT-100 from DEC is another example of a widely-used
so-called "dumb" terminal. A variation of this kind of terminal is
being revived in the idea of the thin client or network computer.
4) The term is sometimes used to mean any personal computer or user workstation that is hooked up to a network. |
| |
| TERMINAL EMULATOR |
In
computers, an emulator is a hardware device or a program that pretends
to be another particular device or program that other components expect
to interact with. For example, using a 3270 emulator, a program written
to be used with the 3270 Display Terminal can communicate with and
control a PC as though it were a 3270. Typically, an emulator is
provided when a popular hardware device becomes outdated and no longer
marketed but legacy programs exist that still need to communicate with
the older device. The practice of using an emulator to make an older
program work with a new end-use device is called terminal emulation. |
| |
| TERMINAL SERVER |
Generally
in information technology, a terminal server is a hardware device or
server that provides terminals (PCs, printers, and other devices) with
a common connection point to a local or wide area network. The
terminals connect to the terminal server from their RS-232 or RS-423
serial ports. The other side of the terminal server connects through
network interface cards (NICs) to a local area network (LAN), usually
an Ethernet or Token Ring LAN, through modems to the dial-in/out wide
area network, or to an X.25 network or a 3270 gateway. (Different makes
of terminal server offer different kinds of interconnection. Some can
be ordered in different configurations based on customer need.) The use
of a terminal server means that each terminal doesnt need its own
network interface card or modem. The connection resources inside the
terminal server are usually shared dynamically by all attached
terminals.
Some terminal
servers can be shared by up to 128 terminals. The terminals can be PCs,
terminals that emulate 3270s, printers, or other devices with the
RS-232/423 interface. In some terminal servers, the terminals can use
TCP/IP for Telnet connection to a host, LAT to a DEC host, or TN3270
for Telnet connection to an IBM host with 3270 applications. With some
terminal servers, a given terminal user can have multiple host
connections to different kinds of host operating systems (UNIX, IBM,
DEC). |
| |
| THUMBNAIL |
A
graphic or image purposely made smaller in size in order to display
multiple images on the same Web page at the same time. A popular
practice on the Web because it gives the user the chance to choose the
image they would like to see a larger version of. This is usually done
by clicking your mouse on it.
The practice of using thumbnails is also used to display "samples" of
images that are "free" thus, when a user click on it, they either need
to enter in a password in order to get at it, or they are instructed on
how to provide payment for the higher resolution larger version, before
they can actually see it. |
| |
| TIA |
Abbreviations of Thanks In Advance, commonly used in newsgroup postings. |
| |
| TIMEOUT |
The facility whereby after a certain period of inactivity the connection or line is dropped. |
| |
| TROJAN |
A
type of computer virus which comes disguised as a program. People
download this program usually from the Internet because they think that
the program is of some use, but once they start it up it could perhaps
erase your hard drive or just wreak havoc all over your system.
Recently there has been a discovery of a Trojan Horse type virus which
comes in the form of a file called AOL4FREE.COM this file should NOT be
downloaded to your system by any means. The name comes from the Greek
legend of a horse that looks benevolent at first but really holds
trouble. |
| |
| UDP |
UDP
(User Datagram Protocol) is a communications method (protocol) that
offers a limited amount of service when messages are exchanged between
computers in a network that uses the Internet Protocol (IP). UDP is an
alternative to the Transmission Control Protocol (TCP) and, together
with IP, is sometimes referred to as UDP/IP. Like the Transmission
Control Protocol, UDP uses the Internet Protocol to actually get a data
unit (called a datagram) from one computer to another. Unlike TCP,
however, UDP does not provide the service of dividing a message into
packets (datagrams) and reassembling it at the other end. Specifically,
UDP doesnt provide sequencing of the packets that the data arrives in.
This means that the application program that uses UDP must be able to
make sure that the entire message has arrived and is in the right
order. Network applications that want to save processing time because
they have very small data units to exchange (and therefore very little
message reassembling to do) may prefer UDP to TCP. The Trivial File
Transfer Protocol (TFTP) uses UDP instead of TCP.
UDP provides two services not provided by the IP layer. It provides
port numbers to help distinguish different user requests and,
optionally, a checksum capability to verify that the data arrived
intact.
In the Open Systems Interconnection (OSI) communication model, UDP, like TCP, is in layer 4, the Transport Layer.
|
| |
| UENCODE |
Uuencode
(also called Uuencode/Uudecode) is a popular utility for encoding and
decoding files exchanged between users or systems in a network. It
originated for use between users of UNIX systems (its name stood for
"UNIX-to-UNIX encoding"). However, its available or easily obtainable
for use in all operating systems and most email applications provide it
as an encoding alternative, especially for email attachments. If youre
sending email with an attachment and you suspect your recipient(s) may
not have a MIME-compliant system (for example, an older PC or UNIX
system), you may want to specify "Uuencode" for the attachment to an
email note. (In Eudora, when writing a note, look for the little box
set to a default of "MIME" and change it to "Uuencode.")
Basically, what Uuencode does is to translate or convert a file or
email attachment (it can be an image, a text file, or a program) from
its binary or bit-stream representation into the 7-bit ASCII set of
text characters. Text can be handled by older systems that may not
handle binary files well and larger files can be more easily divided
into multi-part transmissions. |
| |
| UNIX |
UNIX
is an operating system that originated at Bell Labs in 1969 as an
interactive time-sharing system. Ken Thompson and Dennis Ritchie are
considered the inventors of UNIX. The name (pronounced YEW-nihks) was a
pun based on an earlier system, Multics. In 1974, UNIX became the first
operating system written in the C language. UNIX has evolved as a kind
of large freeware product, with many extensions and new ideas provided
in a variety of versions of UNIX by different companies, universities,
and individuals. Partly because it was not a proprietary operating
system owned by any one of the leading computer companies and partly
because it is written in a standard language and embraced many popular
ideas, UNIX became the first open or standard operating system that
could be improved or enhanced by anyone. A composite of the C language
and shell (user command) interfaces from different versions of UNIX
were standardized under the auspices of the IEEE as the Portable
Operating System Interface (POSIX). In turn, the POSIX interfaces were
specified in the X/Open Programming Guide 4.2 (also known as the
"Single UNIX Specification" and "UNIX 95"). Version 2 of the Single
UNIX Specification is also known as UNIX 98. The "official" trademarked
UNIX is now owned by the The Open Group, an industry standards
organization, which certifies and brands UNIX implementations.
UNIX operating systems are used in widely-sold workstation products
from Sun Microsystems, Silicon Graphics, IBM, and a number of other
companies. The UNIX environment and the client/server program model
were important elements in the development of the Internet and the
reshaping of computing as centred in networks rather than in individual
computers. Linux, a UNIX derivative available in both "free software"
and commercial versions, is increasing in popularity as an alternative
to proprietary operating systems. |
| |
| UNZIP |
Unzipping
is the act of extracting the files from a zip file or similar file
archive. If the files in the package were also compressed (as they
usually are), unzipping also uncompresses them.
When you download programs from shareware or freeware companies on the
Web, they almost always send you a zipped file (the file name has a
suffix of ".zip"). You can usually extract the files from a zipped file
just by double-clicking on it since many archives include a
"self-extracting" program. Several popular tools exist for zipping and
unzipping: PKZIP in the DOS operating system, WinZip in Windows, and
MacZip in Macintosh. |
| |
| UPLOAD |
Uploading
is the transmission of a file from one computer system to another,
usually larger computer system. From a network user's point-of-view, to
upload a file is to send it to another computer that is set up to
receive it. People who share images with others on bulletin board
services (BBS's) upload files to the BBS.
Downloading is transmission in the other direction: from one, usually
larger computer to another, usually smaller computer. From an Internet
user's point-of-view, downloading is receiving a file from another
computer.
The File Transfer Protocol (FTP) is the Internet facility for
downloading and uploading files. (If you are uploading a file to
another site, you must usually have permission in advance to access the
site and the directory where the file is to be placed.)
When you send or receive an attached file with an email note, this is
just an attachment, not a download or an upload. However, in practice,
many people use "upload" to mean "send" and "download" to mean receive.
The term is used loosely in practice and if someone says to you
"Download (or upload) such--and-such a file to me" via email, they
simply mean "Send it to me."
In short, from the ordinary workstation or small computer user's
point-of-view, to upload is to send a file and to download is to
receive a file. |
| |
| UPS |
A
UPS (uninterruptible power supply) is a device that allows your
computer to keep running for at least a short time when the primary
power source is lost. It also provides protection from power surges. A
UPS contains a battery that "kicks in" when the device senses a loss of
power from the primary source. If you are using the computer when the
UPS notifies you of the power loss, you have time to save any data you
are working on and exit gracefully before the secondary power source
(the battery) runs out. When all power runs out, any data in your
computer's random access memory (RAM) is erased. When power surges
occur, a UPS intercepts the surge so that it doesn't damage your
computer. |
| |
| URL |
A
URL (Uniform Resource Locator) (pronounced YU-AHR-EHL or, in some
quarters, UHRL) is the address of a file (resource) accessible on the
Internet. The type of resource depends on the Internet application
protocol. Using the World Wide Webs protocol, the Hypertext Transfer
Protocol (HTTP) , the resource can be an HTML page (like the one youre
reading), an image file, a program such as a CGI application or Java
applet, or any other file supported by HTTP. The URL contains the name
of the protocol required to access the resource, a domain name that
identifies a specific computer on the Internet, and a hierarchical
description of a file location on the computer.
On the Web (which uses the Hypertext Transfer Protocol), an example of a URL is:
http://www.mhrcc.org/kingston
which describes a Web page to be accessed with an HTTP (Web browser)
application that is located on a computer named www.mhrcc.org. The
specific file is in the directory named /kingston and is the default
page in that directory (which, on this computer, happens to be named
index.html). |
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| USENET |
Usenet
is a collection of notes on various subjects that are posted to servers
on a worldwide network. Each subject collection of posted notes is
known as a newsgroup. There are thousands of newsgroups and it is
possible for you to form a new one. Most newsgroups are hosted on
Internet-connected servers, but they can also be hosted from servers
that are not part of the Internet. Usenets original protocol was
UNIX-to-UNIX Copy (UUCP), but today the Network News Transfer Protocol
(NNTP) is used.
Most browsers,
such as those from Netscape and Microsoft, provide Usenet support and
access to any newsgroups that you select. On the Web, Deja News and
other sites provide a subject-oriented directory as well as a search
approach to newsgroups and help you register to participate in them. In
addition, there are other newsgroup readers, such as Knews, that run as
separate programs. |
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| V90 |
V.90
is a standard, approved by the International Telecommunications Union
(ITU), for transmitting data downstream to modems at 56 Kbps (thousand
bits per second). The V.90 standard was arrived at by combining the x2
technology from US Robotics (now part of 3Com) and the K56flex
technology from Rockwell. Transmission upstream from a computer modem
is slower than downstream (about 33 Kbps) since it requires
digital-to-analog conversion.
56 Kbps transmission technologies exploit the fact that most telephone
company offices are interconnected with digital lines. Assuming your
Internet connection provider has a digital connection to its telephone
company office, the downstream traffic from your local Internet access
provider can use a new transmission technique on your regular
twisted-pair phone line that bypasses the usual digital-to-analog
conversion. A V.90 modem doesn't need to demodulate the downstream
data. Instead, it decodes a stream of multi-bit voltage pulses
generated as though the line was equipped for digital information.
(Upstream data still requires digital-to-analog modulation.)
Unlike ISDN, the 56 Kbps technologies do not require any additional
installation or extra charges from your local phone company. On the
other hand, the maximum transmission speed of ISDN is twice that of
V.90 at 128 Kbps. You also have the flexibility of combining digital
and voice transmission on the same line. |
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| VERONICA |
Veronica
is a program that allows you to search the files of the Internets
Gopher servers for a particular search string. Like Archie, Veronicas
equivalent program for FTP servers, Veronica is an indexing spider that
visits the Gopher sites, reads all the directory and file names, and
then indexes them in one large index. A user can then query Veronica,
which checks the query against its index. To use Veronica, you can
Telnet or link through your Web browser to a server that you know has
Veronica on it and then enter search commands.
Veronica and Archie are perhaps of most use for serious researchers who
have already tried the Webs main search engines first or who already
know that the topic of their search is likely to be found on Gopher and
FTP servers. |
| |
| VIRUS |
A
virus is a piece of programming code inserted into other programming to
cause some unexpected and, for the victim, usually undesirable event.
Viruses can be transmitted by downloading programming from other sites
or be present on a diskette. The source of the file you are downloading
or of a diskette you have received is often unaware of the virus. The
virus lies dormant until circumstances cause its code to be executed by
the computer. Some viruses are playful in intent and effect ("Happy
Birthday, Ludwig!") and some can be quite harmful, erasing data or
causing your hard disk to require reformatting.
Generally, there are three main classes of viruses:
File infectors. These viruses attach themselves to program files,
usually selected .COM or .EXE files. Some can infect any program for
which execution is requested, including .SYS, .OVL, .PRG, and .MNU
files. When the program is loaded, the virus is loaded as well.
System or boot-record infectors. These viruses infect executable code
found in certain system areas on a disk. They attach to the DOS boot
sector on diskettes or the Master Boot Record on hard disks. A typical
scenario (familiar to the author) is to receive a diskette from an
innocent source that contains a boot disk virus. When your operating
system is running, files on the diskette can be read without triggering
the boot disk virus. However, if you leave the diskette in the drive,
and then turn the computer off or reload the operating system, the
computer will look first in your A drive, find the diskette with its
boot disk virus, load it, and make it temporarily impossible to use
your hard disk. (Allow several days for recovery.) This is why you
should make sure you have a bootable floppy.
Macro viruses. These are among the most common viruses, and they tend
to do the least damage. Macro viruses infect your Microsoft Word
application and typically insert unwanted words or phrases.
The best protection against a virus is to know the origin of each
program or file you load into your computer. Since this is difficult,
you can buy anti-virus software that typically checks all of your files
periodically and can remove any viruses that are found. From time to
time, you may get an email message warning of a new virus. Chances are
good that the warning is a virus hoax. |
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| VPN |
A
virtual private network (VPN) is a private data network that makes use
of the public telecommunication infrastructure, maintaining privacy
through the use of a tunnelling protocol and security procedures. A
virtual private network can be contrasted with a system of owned or
leased lines that can only be used by one company. The idea of the VPN
is to give the company the same capabilities at much lower cost by
using the shared public infrastructure rather than a private one. Phone
companies have provided secure shared resources for voice messages. A
virtual private network makes it possible to have the same secure
sharing of public resources for data. Companies today are looking at
using a private virtual network for both extranets and wide-area
intranets.
Using a virtual
private network involves encrypting data before sending it through the
public network and decrypting it at the receiving end. An additional
level of security involves encrypting not only the data but also the
originating and receiving network addresses. Microsoft, 3Com, and
several other companies have developed the Point-to-Point Tunneling
Protocol (PPTP) and Microsoft has extended Windows NT to support it.
VPN software is typically installed as part of a companys firewall
server. |
| |
| WAIS |
Wide-area
information servers (WAIS) is an Internet system in which specialized
subject databases are created at multiple server locations, kept track
of by a directory of servers at one location, and made accessible for
searching by users with WAIS client programs. The user of WAIS is
provided with or obtains a list of distributed databases. The user
enters a search argument for a selected database and the client then
accesses all the servers on which the database is distributed. The
results provide a description of each text that meets the search
requirements. The user can then retrieve the full text.
WAIS (pronounced "ways") uses its own Internet protocol, an extension
of the Z39.50 standard (Information Retrieval Service Definition and
Protocol Specification for Library Applications) of the National
Information Standards Organization. Web users can use WAIS by either
downloading a WAIS client and a "gateway" to the Web browser or by
using Telnet to connect to a public WAIS client.
Most Web users will find that the abundance of server files and search
engines already available on the Web will make WAIS superfluous.
However, librarians, medical researchers, and others may find some
specialized information available through WAIS that is not currently
available on the Web. |
| |
| WAN |
A
WAN (wide area network) is a geographically dispersed
telecommunications network and the term distinguishes a broader
telecommunication structure from a local area network (LAN). A wide
area network may be privately owned or rented, but the term usually
connotes the inclusion of public (shared user) networks. An
intermediate form of network in terms of geography is a metropolitan
area network (MAN). |
| |
| WAP |
The
WAP (Wireless Application Protocol) is a specification for a set of
communication protocols to standardize the way that wireless devices,
such as cellular telephones and radio transceivers, can be used for
Internet access, including email, the World Wide Web, newsgroups, and
Internet Relay Chat (IRC). While Internet access has been possible in
the past, different manufacturers have used different technologies. In
the future, devices and service systems that use WAP will be able to
interoperate.
The WAP layers are:
Wireless Application Environment (WAE)
Wireless Session Layer (WSL)
Wireless Transport Layer Security (WTLS)
Wireless Transport Layer (WTP)
The WAP was conceived by four companies: Ericsson, Motorola, Nokia, and Unwired Planet (which is now Phone.com). |
| |
| WAREZ |
Warez
(pronounced as though spelled "wares" or possibly by some pronounced
like the city of "Juarez") is a term used by software "pirates" to
describe software that has been stripped of its copy-protection and
made available on the Internet for downloading. People who create warez
sites sometimes call them "warez sitez" and use "z" in other
pluralizations. In our brief investigation of warez sites, we found a
number of sites to be permanently "under construction." Several
included freeware and shareware that is legally downloadable. |
| |
| WEBCAM |
A
cam, homecam, or webcam is a video camera, usually attached directly to
a computer, whose current or latest image is requestable from a Web
site. A live cam is one that is continually providing new images that
are transmitted in rapid succession or, in some cases, in streaming
video. Sites with live cams sometimes imbed them as Java applets in Web
pages. Cams have caught on; there are now (we estimate) several
thousand sites with cams. The first cams were positioned mainly on fish
tanks and coffee machines. Many of today's live cams are on
sex-oriented sites. For travel promotion, traffic information, and the
remote visualization of any ongoing event that's interesting, webcams
seem like an exciting possibility that will become more common as users
get access to more bandwidth. |
| |
| WEBMASTER |
A Webmaster is a person who either:
Creates and manages the information content (words and pictures) and organization of a Web site.
Manages the computer server and technical programming aspects of a Web site
Or does both.
Companies advertising for a Webmaster vary in their use of the term. In
a smaller company, a Webmaster typically "does it all." In a larger
company, a Webmaster tends to be someone with either a writing and/or
graphics design background who has acquired Web site creation skills
(mainly knowledge and experience with HTML) or a more technical person
with some programming skills. The "technical" Webmaster runs the server
(for example, by managing the creation and authorization associated
with file systems) and writes programs or PERL scripts required by the
Web site.
In a very large corporation, there may be a Webmaster team of people at
the top of the corporation who establish the overall corporate Web
design and policies, arrange the necessary technical resources (working
with the people who provide the corporation its network
infrastructure), and supervise the design of the corporation's Web site
(which is often done by an outside firm). At division and product
levels, there may be additional Webmasters who organize and develop the
Web content and programming for their division or product. In addition,
there is likely to be an interrelated effort to create a Web design,
organization, and content for the corporation's intranet.
At a small corporation, the Webmaster may be in charge of creating the
site and putting it on a separate company's server or setting up one
within the company. The Web design and creation may be done initially
by an outside Web design firm that turns the finished site over to the
company's in-house Webmaster to maintain and perhaps add content within
the established design.
And if you are a firm that specializes in creating Web sites, you may
refer to the overall producer or art director as the Webmaster for a
site. Obviously, this term (and job) is is still defining itself. A
Webmaster is what a company says one is. In general, almost any
Webmaster would be expected to know the Hypertext Markup Language
(HTML) and have a good understanding of why a company should want a Web
site. |
| |
| WINSOCK |
Winsock
- a Micorsoft Windows DLL file that provides the interface to TCP/IP
services, essentially allowing Windows to use Web browsers, FTP
programs, and others. |
| |
| WINZIP |
WinZip
is a Windows program that lets you archive and compress files so that
you can store or distribute them more efficiently. WinZip is a more
capable and easier-to-use Windows equivalent of two earlier programs,
commonly used in the DOS operating system, PKZIP and PKUNZIP. Using
WinZip, you can create, open, or expand file packages or archives that
are called zip files. WinZip has a simple drag-and-drop interface that
allows you to view individual files in a zip file without unzipping the
file. WinZip will also launch installation programs from a zip file and
automatically clean up after the installation.
When creating a zip file (or archive), you can choose from five levels
of compression, including "None," for each added file. With a
disk-spanning add-on, you can also create a zip file that will span
multiple diskettes.
WinZip also supports other popular Internet file formats, including
tar, gzip, Unix compress, UUencode, BinHex, and MIME. ARJ, LZH, and ARC
files are supported through other programs. WinZip provides an
interface to most virus scanner programs and is available in 16-bit and
32-bit versions. |
| |
| WORM |
1.A search utility on the World Wide Web that locates resources following user-determined guidelines.
2.WORM (Write Once Read Many) device is used to write information to a
master disk from which CD-ROM disks are replicated. It can only be
written to once. An additional updating would require that the disk be
demagnified and the entire content be written to the disk all over
again. |
| |
| WWW |
World
Wide Web -- Frequently used (incorrectly) when referring to "The
Internet", WWW has two major meanings - First, loosely used: the whole
constellation of resources that can be accessed using Gopher, FTP,
HTTP, telnet, USENET, WAIS and some other tools. Second, the universe
of hypertext servers (HTTP servers) which are the servers that allow
text, graphics, sound files, etc. to be mixed together. |
| |
| XML |
(Extensible
Markup Language) is a flexible way to create common information formats
and share both the format and the data on the World Wide Web,
intranets, and elsewhere. For example, computer makers might agree on a
standard or common way to describe the information about a computer
product (processor speed, memory size, and so forth) and then describe
the product information format with XML. Such a standard way of
describing data would enable a user to send an intelligent agent (a
program) to each computer maker's Web site, gather data, and then make
a valid comparison. XML can be used by any individual or group of
individuals or companies that wants to share information in a
consistent way.
Currently a
formal recommendation from the World Wide Web Consortium (W3C). XML is
similar to the language of today's Web pages, HTML. Both XML and HTML
contain markup symbols to describe the contents of a page or file.
HTML, however, describes the content of a Web page (mainly text and
graphic images) only in terms of how it is to be displayed and
interacted with.
For example,
a could indicate that the data that followed it was
a phone number. This means that an XML file can be
processed purely as data by a program or it can be
stored with similar data on another computer or,
like an HTML file, that it can be displayed.
For
example, depending on how the application in the
receiving computer wanted to handle the phone number,
it could be stored, displayed, or dialed.
XML is "extensible" because, unlike HTML, the markup symbols are unlimited and
self-defining. XML is actually a simpler and easier-to-use subset of the Standard
Generalized Markup Language (SGML), the standard for how to create a document
structure.
It is expected that HTML and XML will be used together in many Web
applications.
Early applications of XML include Microsoft's Channel Definition Format (CDF),
which describes a channel, a portion of a Web site that has been downloaded to
your hard disk and is then is updated periodically as information changes.
A
specific CDF file contains data that specifies an initial Web page and how frequently
it is updated. Another early application is ChartWare, which uses XML as a way
to describe medical charts so that they can be shared by doctors.
Applications
related to banking, e-commerce ordering, personal preference profiles, purchase
orders, litigation documents, part lists, and many others are anticipated. |
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| XMODEM |
Xmodem
is an error-correcting protocol for modems that was created in 1978 by
Ward Christensen and became a de facto standard. Modems that agree on
using the Xmodem protocol send data in 128-byte blocks. If a block is
received successfully, a positive (ACK) acknowledgement is returned. If
an error is detected, a negative (NAK) acknowledgement is returned and
the block is resent. Xmodem uses the checksum method of error checking. |
|
| ZMODEM |
Zmodem
is an error-correcting protocol for modems. Modems that agree on using
the Zmodem protocol send data in 512-byte blocks. If a block arrives
and an error is detected, a NAK (negative acknowledgement) is returned
and the block is resent.
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