Glossary of Computer Terms

 
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ADN -- (Advanced Digital Network)
Usually refers to a 56Kbps leased-line.

See also: Leased Line

ADSL -- (Asymmetric Digital Subscriber Line)
A DSL line where the upload speed is different from the download speed. usually the download speed is much greater.

See also: DSL , SDSL

Anonymous FTP

See also: FTP

Applet
A small Java program that can be embedded in an HTML page. Applets differ from full-fledged Java applications in that they are not allowed to access certain resources on the local computer, such as files and serial devices (modems, printers, etc.), and are prohibited from communicating with most other computers across a network. The common rule is that an applet can only make an Internet connection to the computer from which the applet was sent.

See also: HTML , Java

Archie
A tool (software) for finding files stored on anonymous FTP sites. You need to know the exact file name or a substring of it. By 1999 Archie had been almost completely replaced by web-based search engines. back when FTP was the main way people moved files over the Internet archie was quite popular.

See also: FTP

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 to connect together computers that were each running different system so that people at one location could use computing resources from another location.

See also: Internet (Upper case I) , Network , WAN

ASCII -- (American Standard Code for Information Interchange)
This is the defacto world-wide standard for the code numbers used by computers to represent all the upper and lower-case Latin letters, numbers, punctuation, etc. There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111.

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Backbone
A high-speed line or series of connections that forms a major pathway within a network. The term is relative as a backbone in a small network will likely be much smaller than many non-backbone lines in a large network.

See also: Network

Bandwidth
How much stuff you can send through a connection. Usually measured in bits-per-second. A full page of English text is about 16,000 bits. A fast modem can move about 57,000 bits in one second. Full-motion full-screen video would require roughly 10,000,000 bits-per-second, depending on compression.

See also: Bit , bps , T-1

Baud
In common usage the baud rate of a modem is how many bitsit can send or receive per second. Technically, baud is the number of times per second that the carrier signal shifts value - for example a 1200 bit-per-second modem actually runs at 300 baud, but it moves 4 bits per baud (4 x 300= 1200 bits per second).

See also: Bit , Modem

BBS -- (Bulletin Board System)
A computerized meeting and announcement system that allows people to carry on discussions, upload and download files, and make announcements without the people being connected to the computer at the same time. In the early 1990's there were many thousands (millions?) of BBS?s around the world, most are very small, running on a single IBM clone PC with 1 or 2 phone lines. Some are very large and the line between a BBS and a system like AOL gets crossed at some point, but it is not clearly drawn.

Binary
Information consisting entirely of ones and zeros. Also, commonly used to refer to files that are not simply text files, e.g. images.

See also: MIME , UUENCODE

Binhex -- (BINary HEXadecimal)
A method for converting non-text files (non-ASCII) into ASCII. This is needed because Internet e-mail can only handle ASCII.

See also: ASCII , MIME , UUENCODE

Bit -- (Binary DigIT)
A single digit number in base-2, in other words, either a 1 or a zero. The smallest unit of computerized data. Bandwidthis usually measured in bits-per-second.

See also: Bandwidth , Bit , bps , Byte , Kilobyte , Megabyte

BITNET -- (Because It's Time NETwork (or Because It's There NETwork))
A network of educational sites separate from the Internet, but e-mail is freely exchanged between BITNET and the Internet. Listservs®, a popular form of e-mail discussion groups, originated on BITNET. BITNET machines are usually mainframes running the VMS operating system, and the network is probably the only international network that is shrinking.

bps -- (Bits-Per-Second)
A measurement of how fast data is moved from one place to another. A 56K modem can move about 57,000 bits per second.

See also: Bandwidth , Bit

Browser
A Client program (software) that is used to look at various kinds of Internet resources.

See also: Client , Server , URL , WWW

BTW -- (By The Way)
A shorthand appended to a comment written in an online forum.

See also: IMHO

Byte
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.

See also: Bit

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CATP -- (Caffeine Access Transport Protocol)
Common method of moving caffeine across Wide Area Networks such as the Internet

CATP was first used at the Binary Cafe in Cybertown and quickly spread world-wide.

There are reported problems with short-circuits and rust and decaffinated beverages were not supprted until version 1.5.3

See also: Internet (Upper case I) , IRC , WAN

Certificate Authority
An issuer of Security Certificates used in SSL connections.

See also: SSL

CGI -- (Common Gateway Interface)
A set of rules that describe how a Web Server communicates with another piece of software on the same machine, and how the other piece of software (the ?CGI program?) talks to the web server. Any piece of software can be a CGI program if it handles input and output according to the CGI standard.

See also: Server , WWW

cgi-bin
The most common name of a directory on a web server in which CGIprograms are stored.

See also: CGI

Client
A software program that is used to contact and obtain data from a Server software program on another computer, often across a great distance. EachClient program is designed to work with one or more specific kinds of Server programs, and each Server requires a specific kind of Client. A Web Browser is a specific kind of Client.

See also: Browser , Client , Server

co-location
Most often used to refer to having a server that belongs to one person or group physically located on an Internet-connected network that belongs to another person or group. Usually this is done because the server owner wants their machine to be on a high-speed Internet connection and/or they do not want the security risks of having the server on thier own network.

See also: Internet (Upper case I) , Network , Server

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 Browsers' 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 users' 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 CIA, but they can be used to gather more information about a user than would be possible without them.

See also: Browser , Server

Cyberpunk
Cyberpunk was originally a cultural sub-genre of science fiction taking place in a not-so-distant, dystopian, over-industrialized society. The term grew out of the work of William Gibson and Bruce Sterling and has evolved into a cultural label encompassing many different kinds of human, machine, and punk attitudes. It includes clothing and lifestyle choices as well.

See also: Cyberspace

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.

See also: Cyberpunk

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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 regardsto the digital revolution.

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: 
matisse.net
mail.matisse.net
workshop.matisse.net
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 (matisse.net 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 e-mail 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.

See also: IP Number

DSL -- (Digital Subscriber Line)
A method for moving data over regular phone lines. A DSL circuit is much faster than a regular phone connection, and the wires coming into the subscriber's premises are the same (copper) wires used for regular phone service. A DSL circuit must be configured to connect two specific locations, similar to a leased line (howeverr a DSL circuit is not a leased line.

A common configuration of DSL allows downloads at speeds of up to 1.544 megabits (not megabytes) per second, and uploads at speeds of 128 kilobits per second. This arrangement is called ADSL: Asymmetric Digital Subscriber Line.

Another common configuration is symmetrical: 384 Kilobits per second in both directions.

In theory ADSL allows download speeds of up to 9 megabits per second and upload speeds of up to 640 kilobits per second.

DSL is now a popular alternative to Leased Lines and ISDN, being faster than ISDN and less costly than traditional Leased Lines.

See also: ADSL , Bandwidth , ISDN , Leased Line , SDSL

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Email -- (Electronic Mail)
Messages, usually text, sent from one person to another via computer. E-mail can also be sent automatically to a large number of addresses.

See also: Listserv ® , SMTP

Ethernet
A very common method of networking computers in a LAN.

There is more than one type of Ethernet. By 2001 the standard type was "100-BaseT" which can handle up to about 100,000,000 bits-per-second and can be used with almost any kind of computer.

See also: Bandwidth , FDDI , LAN

Extranet
An intranet that is accesible to computers that are not hysically part of a companys' own private network, but that is not accessible to the general public, for example to allow vendors and business partners to access a company web site.

Often an intranet will make use of a Virtual Private Network. (VPN.)

See also: Intranet , Network , VPN

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FAQ -- (Frequently Asked Questions)
FAQs are documents that list and answerthe most common questions on a particular subject. There are hundreds of FAQs on subjects as diverse as Pet Grooming and Cryptography. FAQs are usually written by people who have tired of answering the same question over and over.

FDDI -- (Fiber Distributed Data Interface)
A standard for transmitting data on optical fiber cables at a rate of around 100,000,000 bits-per-second (10 times as fast as 10-BaseTEthernet, about twice as fast as T-3).

See also: Ethernet , T-3

Finger
An Internet software tool for locating people on other Internet sites. Finger is also sometimes used to give access to non-personal information, but the most common use is to see if a person has an account at a particular Internet site. Many sites do not allow incoming Finger requests, but many do.

Fire Wall
A combination of hardware and software that separates a Network into two or more parts for security purposes.

See also: Network

Flame
Originally, "flame" meant to carry forth in a passionate manner in the spirit of honorable 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.

See also: Flame War

Flame War
When an online discussion degenerates into a series of personal attacks against the debators, rather than discussion of their positions. A heated exchange.

See also: Flame

FTP -- (File Transfer Protocol)
A very common method of moving files between two Internet sites.

FTP is a way to login to another Internet site for the purposes of retrieving and/or sending files. There are many Internet sites that have established publicly accessible repositories of material that can be obtained using FTP, by logging in using the account name "anonymous", thus these sites are called "anonymous ftp servers".

FTP was invented and in wide use long before the advent of the World Wide Web and originally was always used from a text-only interface.

See also: Login , WWW

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Gateway
The technical meaning is a hardware or software set-up that translates between two dissimilar protocols, for example America Online has a gateway that translates between its internal, proprietary e-mail format and Internet e-mail format. Another, sloppier meaning of gateway is to describe any mechanism for providing access to another system, e.g. AOL might be called a gateway to the Internet.

GIF -- (Graphic Interchange Format)
A common format for image files, especially suitable for images containing large areas of the same color. GIF format files of simple images are often smaller than the same file would be if stored in JPEG format, but GIF format does not store photographic images as well as JPEG.

See also: JPEG

Gigabyte
1000 or 1024 Megabytes, depending on who is measuring.

See also: Byte

Gopher
Invented at the University of Minnesota in 1993 just before the Web, gopher was a widely successful method of making menus of material available over the Internet.

Gopher was designed to be much easier to use than FTP, while still using a text-only interface.

Gopher is a Client and Server style program, whichrequires that the user have a Gopher Client program. Although Gopher spread rapidly across the globe in only a couple of years, it has been largely supplanted by Hypertext, also known as WWW (World Wide Web). There are still thousands of Gopher Servers on the Internet and we can expect they will remain for a while.

See also: Client , FTP , WWW

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hit
As used in reference to the World Wide Web, ?hit? means a single request from a web browser for a single item from a web server; thus in order for a web browser to display a page that contains 3 graphics, 4 ?hits? would occur at the server: 1 for the HTML page, and one for each of the 3 graphics.

See also: Browser , HTML , Server

Home Page (or 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.?

See also: Browser , WWW

Host
Any computer on a network that is a repository for services available to other computers on the network. It is quite common to have one host machine provide several services, such as SMTP (email) and HTTP (web).

See also: Network , SMTP

HTML -- (HyperText Markup Language)
The coding language used to create Hypertext documents for use on the World Wide Web. HTML looks a lot like old-fashioned typesetting code, where you surround a block of text with codes that indicate how it should appear.

The "hyper" in Hypertext comes from the fact that in HTML you can specify that a block of text, or an image, is linked to another file on the Internet. HTML files are meant to be viewed using a "Web Browser".

HTML is loosely based on a more comprehensive system for markup called SGML.

See also: Browser , Hypertext , WWW

HTTP -- (HyperText Transfer Protocol)
The protocol for moving hypertextfiles across the Internet. Requires a HTTP client program on one end, and an HTTP server program on the other end. HTTP is the most important protocol used in the World Wide Web (WWW).

See also: Client , Hypertext , Server , WWW

Hypertext
Generally, any text that contains links to other documents - words or phrases in the document that can be chosen by a reader and which cause another document to be retrieved and displayed.

See also: HTML , HTTP

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IMAP -- (Internet Message Access Protocol)
IMAP is gradually replacing POP as the main protocol used by email clients in communicating with email servers.

Using IMAP an email client program can not only retrieve email but can also manipulate message stored on the server, without having to actually retrieve the messages. So messages can be deleted, have their status changed, multiple mail boxes can be managed, etc.

IMAP is defined in RFC 2060

See also: Email , POP , RFC

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 areexpressing a debatable view, probably on a subject already under discussion. One of many such shorthands in common use online, especially in discussion forums.

internet (Lower case i)
Any time you connect 2 or more networks together, you have an internet - as in inter-national or inter-state.

See also: Internet (Upper case I) , Network

Internet (Upper case I)
The vast collection of inter-connected networks that are connected using the TCP/IP protocols and that evolved from the ARPANET of the late 60's and early 70's.

The Internet connects tens of thousands of independent networks into a vast global internet and is probably the largest Wide Area Network in the world.

See also: internet (Lower case i) , Network , WAN

Intranet
A private network inside a company or organization that uses the same kinds of software that you would find on the public Internet, but that is only for internal use. Compare with extranet.

See also: Extranet , internet (Lower case i) , Internet (Upper case I)

IP Number -- (Internet Protocol Number)
Sometimes called a dotted quad. A unique number consisting of 4 parts separated by dots, e.g. 
    165.113.245.2
Every machine that is on the Internet has a unique IP number - if a machine does not have an IP number, it is not really on the Internet. Many machines (especially servers) also have one or more Domain Names that are easier for people to remember.

See also: Domain Name , Server , TCP/IP

IRC -- (Internet Relay Chat)
Basically a huge multi-user live chat facility. There are a number of major IRC servers around the world which are linked to each other. Anyone can create a channel and anything that anyone types in a given channel is seen by all others in the channel. Private channels can (and are) created for multi-person conference calls.

See also: Server

ISDN -- (Integrated Services Digital Network)
Basically a way to move more dataover existing regular phone lines. ISDN is available to much of the USA and in most markets it is priced very comparably to standard analog phone circuits. It can provide speeds of roughly 128,000 bits-per-second over regular phone lines. In practice, most people will be limited to 56,000or 64,000 bits-per-second.

Unlike DSL, ISDN can be used to connect to many different locations, one at a time, just like a regular telephone call, as long the other location also has ISDN.

See also: DSL

ISP -- (Internet Service Provider)
An institution that provides access to the Internet in some form, usually for money.

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Java
Java is a network-friendly programming language invented by Sun Microsystems.

Java is often used to build large, complex systems that involve several different computers interacting across networks, for example transaction processing systems.

Java is also becoming popular for creating programs that run in small electronic devicws, such as mobile telephones.

A very common use of Java is to create programs that can be safely downloaded to your computer through the Internet and immediately run without fear of viruses or other harm to your computer or files. Using small Java programs (called "Applets"), Web pages can include functions such as animations,calculators, and other fancy tricks.

See also: Applet , JDK

JavaScript
JavaScript is a programming language that is mostly used in web pages, usually to add features that make the web page more interactive. When JavaScript is included in an HTML file it relies upon the browser to interpret the JavaScript. When JavaScript is combined with Cascading Style Sheets(CSS), and later versions of HTML (4.0 and later) the result is often called DHTML.

See also: HTML

JDK -- (Java Development Kit)
A software development package from Sun Microsystems that implements the basic set of tools needed to write, test and debugJava applications and applets

See also: Applet , Java

JPEG -- (Joint Photographic Experts Group)
JPEG is most commonly mentioned as a format for image files. JPEG format is preferred to the GIF format for photographic images as opposed to line art or simple logo art.

See also: GIF

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Kilobyte
A thousand bytes. Actually, usually 1024 (210) bytes.

See also: Byte

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LAN -- (Local Area Network)
A computer network limited to the immediate area, usually the same building or floor of a building.

See also: Network , VPN , WAN

Leased Line
Refers to line such as a telephone line or fiber-optic cable that is rented for exclusive 24-hour, 7-days-a-week use from your location to another location. The highest speed data connections require a leased line.

See also: DSL , ISDN

Listserv ®
The most common kind of maillist, "Listserv" is a registered trademark of L-Soft international, Inc. Listservs originated on BITNET but they are now common on the Internet.

See also: BITNET , Internet (Upper case I) , Maillist

Login
Noun or a verb.

Noun: The account name used to gain access to a computer system. Not a secret (contrast with Password).

Verb: the act of connecting to a computer system by giving your credentials (usually your "username" and "password")

See also: Password

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Maillist
(or Mailing List) A (usually automated) system that allows people to send e-mail to one address, whereupon their message is copied and sent to all of the other subscribers to the maillist. In this way, people who have many different kinds of e-mail access can participate in discussions together.

See also: Email , Listserv ®

Megabyte
A million bytes. Actually, technically, 1024 kilobytes.

See also: Byte , Kilobyte

MIME -- (Multipurpose Internet Mail Extensions)
Originally a standard for defining the types of files attached to standard Internet mail messages. The MIME standard has come to be used in many situations where one cmputer programs needs to communicate with another program about what kind of file is being sent.

For example, HTML files have a MIME-type of text/html, JPEG files are image/jpeg, etc.

See also: HTML , JPEG

Mirror
Generally speaking, "to mirror" is to maintain an exact copy of something. Probably the most common use of the term on the Internet refers to "mirror sites" which are web sites, or FTP sites that maintain copies of material originated at another location, usually in order to provide more widespread access to the resource. For example, one site might create a library of software, and 5 other sites might maintain mirrors of that library.

See also: FTP , WWW

Modem -- (MOdulator, DEModulator)
A device that connects a computer to a phone line. A telephone for a computer. A modem allows a computer to talk to other computers through the phone system. Basically, modems do for computers what a telephone does for humans.

MOO -- (Mud, Object Oriented)
One of several kinds of multi-user role-playing environments.

See also: MUD

Mosaic
The first WWW browser that was available for the Macintosh, Windows,and UNIX all with the same interface. Mosaic really started the popularity of the Web. The source-code to Mosaic was licensed by several companies and used to create many other web browsers.

Mosaic was developed at the National Center for Supercomputing Applications (NCSA), at the Univeristy of Urbana-Champange in Illinois, USA. The first version was released in late 1993.

See also: Browser , WWW

MUD -- (Multi-User Dungeon or Dimension)
A (usually text-based) multi-user simulation environment. Some are purely for fun and flirting, others are used for serious software development, or education purposes and all thatlies in between. A significant feature of most MUDs is that users can create things that stay after they leave and which other users can interact within their absence, thus allowing a world to be built gradually and collectively.

See also: MOO

MUSE -- (Multi-User Simulated Environment)
One kind of MUD - usually with little or no violence.

See also: MUD

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Netiquette
The etiquette on the Internet.

Netizen
Derived from the term citizen, referring to a citizen of the Internet,or someone who uses networked resources. The term connotes civic responsibility and participation.

Netscape
A WWW Browser and the name of a company. The Netscape (tm) browser was originally based on the Mosaic program developed at the National Center for Supercomputing Applications (NCSA).

See also: Mosaic

Network
Any time you connect 2 or more computers together so that they can share resources, you have a computer network. Connect 2 or more networks together and you have an internet.

See also: internet (Lower case i)

Newsgroup
The name for discussion groups on USENET.

See also: USENET

NIC -- (Network Information Center)
Generally, any office that handles information for a network. The most famous of these on the Internet was the InterNIC, which was where most new domain names were registered until that process was decentralized to a number of private companies.

See also: Domain Name , Network

NNTP -- (Network News Transport Protocol)
The protocol used by clientand server software to carry USENET postings back and forth over a TCP/IP network. If you are using any of the more common software such as Netscape, Nuntius, Internet Explorer, etc. to participate in newsgroups then you are benefiting from an NNTP connection.

See also: Client , Server , TCP/IP

Node
Any single computer connected to a network.

See also: Network

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Open Source Software
Open Source Software is software for which the underlying programming code is available to the users so that they may read it, make changes to it, and build new versions of the software incorporating their changes. There are many types of Open Source Software, mainly differing in the licensing term under which (altered) copies of the source code may (or must be) redistributed.

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Packet Switching
The method used to move data around on the Internet. In packet switching,all the data coming out of a machine is broken up into chunks, each chunk has the address of where it came from and where it is going. This enables chunks of data from many different sources to co-mingle on the same lines, and be sorted and directed along different routes by special machines along the way. This way many people can use the same lines at the same time.

You might think of several caravans of trucks all using the same road system. to carry materials.

See also: Internet (Upper case I) , Router

Password
A code used to gain access (login) to a locked system. Good passwords contain letters and non-letters and are not simple combinations such as virtue7. A good password might be: 
   5%df(29)
But don't use that one!

See also: Login

Plug-in
A (usually small) piece of software that adds features to a larger piece of software. Common examples are plug-ins for the Netscape® browser and web server. Adobe Photoshop® also uses plug-ins.

See also: Browser , Server

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 a way that e-mail client software such as Eudora gets mail from a mail server. When you obtain an account from an Internet Service Provider (ISP) you almost always get a POP account with it, and it is this POP account that you tell your e-mail software to use to get your mail. Another protocol called IMAP is replacing POP for email.

See also: Client , Email , IMAP , ISP , Server

Port
3 meanings. First and most generally, a place where information goes into or out of a computer, or both. E.g. the serial port on a personal computer is where a modem would be connected.

On the Internet port often refers to a number that is part of a URL, appearing after a colon (:) right after the domain name. Every service on an Internet server listens on a particular port number on that server. Most services have standard port numbers, e.g. Web servers normally listen on port 80. Services can also listen on non-standard ports, in which case the port number must be specified in a URL when accessing the server, so you might see a URL of the form: 

    gopher://peg.cwis.uci.edu:7000/
This shows a gopher server running on a non-standard port (the standard gopher port is 70).

Finally, port also refers to translating a piece of software to bring it from one type of computer system to another, e.g. to translate a Windows program so that is will run on a Macintosh.

See also: URL

Portal
Usually used as a marketing term to described a Web site that is or is intended to be the first place people see when using the Web. Typically a "Portal site" has a catalog of web sites, a search engine, or both. A Portal site may also offer email and other service to entice people to use that site as their main "point of entry" (hence "portal") to the Web.

Posting
A single message entered into a network communications system.

PPP -- (Point to Point Protocol)
The most common protocol used to connect home computers to the Internet over regular phone lines.

Most well known as a protocol that allows a computer to use a regular telephone line and a modem to make TCP/IPconnections and thus be really and truly on the Internet.

See also: Modem , SLIP , TCP/IP

Proxy Server
A Proxy Server sits in between a Client and the "real" Server that a Client is trying to use. Client's are sometimes configured to use a Proxy Server, usually an HTTP server. The clients makes all of it's requests from the Proxy Server, which then makes requests from the "real" server and passes the result back to the Client. Sometimes the Proxy server will store the results and give a stored result instead of making a new one (to reduce use of a Network). Proxy servers are commonly established on Local Area Networks

See also: Client , HTTP , LAN , Network , Server

PSTN -- (Public Switched Telephone Network)
The regular old-fashioned telephone system.

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RFC -- (Request For Comments)
The name of the result and the process for creating a standard on the Internet. New standards are proposed and published on the Internet, as a Request For Comments. The proposal is reviewed by the Internet Engineering Task Force (http://www.ietf.org/), a consensus-building body that facilitates discussion, and eventually a new standard is established, but the reference number/name for the standard retains the acronym RFC, e.g. the official standard for e-mail message formats is RFC 822.

Router
A special-purpose computer (or software package) that handles the connection between 2 or more Packet-Switched networks. Routers spend all their time looking at the source and destination addresses of the packets passing through them and deciding which route to send them on.

See also: Network , Packet Switching

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SDSL -- (Symmetric Digital Subscriber Line)
A version of DSL where the upload speeds and download speeds are the same.

See also: ADSL , DSL

Search Engine
A (usually web-based) system for searching the information available on the Web.

Some search engines work by automatically searching the contents of other systems and creating a database of the results. other search engines contains only material manually approved for inclusion in a database, and some combine the two approaches.

See also: WWW

Security Certificate
A chunk of information (often stored as a text file) that is used by the SSL protocol to establish a secure connection.

See also: SSL

Server
A computer, or a software package, that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, such as a WWW server, or to the machine on which the software is running, e.g. "Our mail server is down today, that's why e-mail isn't getting out."

A single server machine can (and often does) have several different server software packages running on it, thus providing many different servers to clients on the network.

See also: Client , Network

SLIP -- (Serial Line Internet Protocol)
A standard for using a regular telephone line (a serial line) and a modem to connect a computer as a realInternet site. SLIP has largely been replaced by PPP.

See also: PPP

SMDS -- (Switched Multimegabit Data Service)
A standard for very high-speed data transfer.

SMTP -- (Simple Mail Transfer Protocol)
The main protocol used to send electronic mail from server to server on the Internet.

SMTP is defined in RFC 821 and modified by many later RFC's

See also: Email , RFC , Server

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.

SNMP is defined in RFC 1089

See also: Network , RFC , Router , TCP/IP

Spam (or Spamming)
An inappropriate attempt to use a mailing list, or USENET or other networked communications facility as if it was a broadcast medium (which it is not) by sending the same message to a large number of people who didn?t ask for it. The term probably comes from a famous Monty Python skit which featured the word spam repeated over and over. The term may also have come from someone?s low opinion of the food product with the same name, which is generally perceived as a generic content-free waste of resources. (Spam® is a registered trademark of Hormel Corporation, for its processed meat product.)

See also: Maillist , USENET

SQL -- (Structured Query Language)
A specialized language for sending queries to databases. Most industrial-strength and many smaller database applications can be addressed using SQL. Each specific application will have its own slightly different version of SQL implementing features unique to that application, but all SQL-capable databases support a common subset of SQL.

A example of an SQl statement is: 

    SELECT name,email FROM people_table WHERE contry='uk'


SSL -- (Secure Socket Layer)
A protocol designed by Netscape Communications to enable encrypted, authenticated communications across the Internet.

Sysop -- (System Operator)
Anyone responsible for the physical operations of a computer system or network resource. For example, a System Administrator decides how often backups and maintenance should be performed and the System Operator performs those tasks.

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T-1
A leased-line connection capable of carrying data at 1,544,000 bits-per-second. At maximum theoretical capacity, a T-1 line could move a megabyte in less than 10 seconds. That is still not fast enough for full-screen, full-motion video, for which you need at least 10,000,000 bits-per-second. T-1 lines are commonly used to connect large LANs to theInternet.

See also: Bit , Flame War , Internet (Upper case I) , LAN , Leased Line

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-motionvideo.

See also: Internet (Upper case I) , LAN , Leased Line

TCP/IP -- (Transmission Control Protocol/Internet Protocol)
This is the suiteof protocols that defines the Internet. Originally designed for the UNIX operating system, TCP/IP software is now included with every major kind of computer operating system. To be truly on the Internet, your computer must have TCP/IP software.

See also: Internet (Upper case I) , Packet Switching , Unix

Telnet
The command and program used to login from one Internet siteto another. The telnet command/program gets you to the login: prompt of another host.

See also: Host , Login

Terabyte
1000 gigabytes.

See also: Gigabyte

Terminal
A device that allows you to send commands to a computer somewhere else. At a minimum, this usually means a keyboard and a display screen and some simple circuitry. Usually you will use terminal software in a personal computer - the software pretends to be (emulates) a physical terminal and allows you to type commands to a computer somewhere else.

Terminal Server
A special purpose computer that has places to plug in many modemson one side, and a connection to a LAN or host machine onthe other side. Thus the terminal server does the work of answering thecalls and passes the connections on to the appropriate node. Mostterminal servers can provide PPP or SLIP services if connectedto the Internet.

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UDP -- (User Datagram Protocol)
One of the protocols for data transfer that is part of the TCP/IP suite of protocols. UDP is a "stateless" protocol in that UDP makes no provision for acknowledgement of packets received.

See also: Packet Switching , TCP/IP

Unix
A computer operating system (the basic software running on a computer, underneath things like word processors and spreadsheets). Unix is designed to be used by many people at the same time (it is multi-user) and has TCP/IP built-in. It is the most common operating system for servers on the Internet.

Apple computers' Macintosh operating system, as of version 10, is based on Unix.

See also: Server , TCP/IP

URI -- (Uniform Resource Identifier)
An address for s resource available on the Internet.

The first part of a URI is called the "scheme". the most well known scheme is http, but there are many others. Each URI scheme has its own format for how a URI should appear.

Here are examples of URIs using the http, telnet, and news schemes: 
    http://www.matisse.net/files/glossary.html
    telnet://well.sf.ca.us
    news:new.newusers.questions

See also: URL , URN

URL -- (Uniform Resource Locator)
The term URL is basically synonymous with URI. URI has replaced URL in technical specifications.

See also: URI , URN

URN -- (Uniform Resource Name)
A URI that is supposed to be available for along time. For an address to be a URN some institution is supposed to make a commitment to keep the resource available at that address.

See also: URI

USENET
A world-wide system of discussion groups, with comments passed among hundreds of thousands of machines. Not all USENET machines are on the Internet. USENET is completely decentralized, with over 10,000 discussion areas, called newsgroups.

See also: Newsgroup

UUENCODE -- (Unix to Unix Encoding)
A method for converting files from Binaryto ASCII (text) so that they can be sent across the Internet viae-mail.

See also: ASCII , Binary , Email

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Veronica -- (Very Easy Rodent Oriented Net-wide Index to Computerized Archives)
Developed at the University of Nevada, Veronica was a constantly updated database of the names of almost every menu item on thousands of gopherservers. The Veronica database could be searched from most major gophermenus.

Now made obsolete by web-bases search engines.

See also: Gopher , Search Engine

VPN -- (Virtual Private Network)
Usually refers to a network in which some of the parts are connected using the public Internet, but the data sent across the Internet is encrypted, so the entire network is "virtually" private.

See also: Internet (Upper case I)

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WAIS -- (Wide Area Information Servers)
A commercial software package that allows the indexing of huge quantities of information, and then making those indices searchable across networks such as the Internet. A prominent feature of WAIS is that the search results are ranked (scored) accordingto how relevant the hits are, and that subsequent searches can find more stuff like that last batch and thus refine the search process.

WAN -- (Wide Area Network)
Any internet or network that covers an area larger than a single building or campus.

See also: internet (Lower case i) , LAN

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.

See also: FTP , Gopher , HTTP , Internet (Upper case I) , URL

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XML -- (eXtensible Markup Language)
A widely used system for defining data formats. XML provides a very rich system to define complex documents and data structures such as invoices, molecular data, news feeds, glossaries, inventory descriptions, real estate properties, etc.

As long as a programmer has the XML definition for a collection of data (often called a "schema") then they can create a program to reliably process any data formatted according to those rules.



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