Glossary of Internet and Security Terms
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- Apache
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The most common web server (or HTTP server) software on the Internet. Apache is an open-source application originally created from a series of changes ("patches") made to a web server written at the National Center for Supercomputing Applications, the same place the Mosiac web browser was created.
Apache is designed as a set of modules, enabling administrators to choose which features they wish to use and making it easy to add features to meet specific needs inlcuding handling protocols other than the web-standard HTTP.See also: HTTP
- Applet
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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
- Application Server
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Server software that manages one or more other pieces of software in a way that makes the managed software available over a network, usually to a Web server. By having a piece of software manage other software packages it is possible to use resources like memory and database access more efficiently than if each of the managed packages responded directly to requests.
- ASP -- (Application Service Provider)
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A organization (usually a business) that runs one or more applications on their own servers and provides (usually for a fee) access to others. Common examples of services provided this way include web-based software such as Calendar systems, Human Resources tools (timesheets, benefits, etc.), and various applications to help groups collaborate on projects.
See also: Application Server, Server
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- Backbone
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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
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How much stuff you can send through a connection. Usually measured in bits-per-second (bps.) 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.
- Baud
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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
- Bit -- (Binary DigIT)
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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.
- bps -- (Bits-Per-Second)
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A measurement of how fast data is moved from one place to another. A 56K modem can move about 57,000 bits per second.
- Broadband
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Generally refers to connections to the Internet with much greater bandwidth than you can get with a modem. There is no specific definition of the speed of a "broadband" connection but in general any Internet connection using DSL or a via Cable-TV may be considered a broadband connection.
- Browser
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A Client program (software) that is used to look at various kinds of Internet resources.
- Byte
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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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- Certificate Authority
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An issuer of Security Certificates used in SSL connections.
See also: SSL
- CGI -- (Common Gateway Interface)
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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.
- cgi-bin
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The most common name of a directory on a web server in which CGIprograms are stored.
See also: CGI
- Client
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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.
- co-location
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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
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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.
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- DHCP -- (Dynamic Host Configuration Protocol)
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DHCP is a protocol by which a machine can obtain an IP number (and other network configuration information) from a server on the local network.
- DNS -- (Domain Name System)
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The Domain Name System is the system that translates Internet domain names into IP numbers. A "DNS Server" is a server that performs this kind of translation.
See also: Domain Name, IP Number, Server
- Domain Name
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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.
- Download
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Transferring data (usually a file) from a another computer to the computer you are are using. The opposite of upload.
See also: Upload
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- Email -- (Electronic Mail)
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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: SMTP
- Ethernet
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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.
- Extranet
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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.)
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- Finger
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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
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A combination of hardware and software that separates a Network into two or more parts for security purposes.
See also: Network
- FTP -- (File Transfer Protocol)
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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.
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- Gateway
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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.
- Gigabyte
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1000 or 1024 Megabytes, depending on who is measuring.
See also: Byte
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- hit
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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.
- Home Page (or Homepage)
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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
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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).
- HTML -- (HyperText Markup Language)
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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.
- HTTP -- (HyperText Transfer Protocol)
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The protocol for moving hypertextfiles across the Internet. Requires a HTTP client program on one end, and an HTTP server program (such as Apache) on the other end. HTTP is the most important protocol used in the World Wide Web (WWW).
- Hypertext
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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.
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- IMAP -- (Internet Message Access Protocol)
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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
- internet (Lower case i)
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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)
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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
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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)
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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
- IPv4 -- (Internet Protocol, version 4)
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The most widley used version of the Internet Protocol (the "IP" part of TCP/IP.)
IPv4 allows for a theoretical maximum of approximately four billion IP Numbers (technically 232), but the actual number is far less due to inefficiencies in the way blocks of numbers are handled by networks. The gradual adoption of IPv6 will solve this problem. - IPv6 -- (Internet Protocol, version 6)
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The successor to IPv4. Already deployed in some cases and gradually spreading, IPv6 provides a huge number of available IP Numbers - over a sextillion addresses (theoretically 2128). IPv6 allows every device on the planet to have its own IP Number.
- ISDN -- (Integrated Services Digital Network)
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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)
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An institution that provides access to the Internet in some form, usually for money.
- IT -- (Information Technology)
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A very general term referring to the entire field of Information Technology - anything from computer hardware to programming to network management. Most medium and large size companies have IT Departments.
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- Kilobyte
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A thousand bytes. Actually, usually 1024 (210) bytes.
See also: Byte
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- LAN -- (Local Area Network)
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A computer network limited to the immediate area, usually the same building or floor of a building.
- Leased Line
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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.
- Linux
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A widely used Open Source Unix-like operating system. Linux was first released by its inventor Linus Torvalds in 1991. There are versions of Linux for almost every available type of computer hardware from desktop machines to IBM mainframes. The inner workings of Linux are open and available for anyone to examine and change as long as they make their changes available to the public. This has resulted in thousands of people working on various aspects of Linux and adaptation of Linux for a huge variety of purposes, from servers to TV-recording boxes.
See also: Open Source Software, Unix
- Login
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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
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(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,
- Megabyte
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A million bytes. Actually, technically, 1024 kilobytes.
- MIME -- (Multipurpose Internet Mail Extensions)
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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 areimage/jpeg, etc. - Mirror
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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.
- Modem -- (MOdulator, DEModulator)
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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.
The maximum practical bandwidth using a modem over regular telephone lines is currently around 57,000 bps. - Back to Index
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- Network
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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)
- NIC -- (Network Information Center)
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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. Also means "Network Interface card", which is the card in a computer that you plug a network cable into.
See also: Domain Name, Network
- NNTP -- (Network News Transport Protocol)
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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.
- Node
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Any single computer connected to a network.
See also: Network
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- Open Content
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Copyrighted information (such as this Glossary) that is made available by the copyright owner to the general public under license terms that allow reuse of the material, often with the requirement (as with this Glossary) that the re-user grant the public the same rights to the modified version that the re-user received from the copyright owner.
Information that is in the Public Domain might also be considered a form of Open Content.
See also: Open Source Software
- Open Source Software
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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.
See also: Open Content
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- Packet Switching
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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
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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
- ping
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To check if a server is running. From the sound that a sonar systems makes in movies, you know, when they are searching for a submarine.
- podcasting or pod-casting
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A form of audio broadcasting using the Internet, podcasting takes its name from a combination of "iPod" and broadcasting. iPod is the immensely popular digital audio player made by Apple computer, but podcasting does not actually require the use of an iPod.
Podcasting involves making one or more audio files available as "enclosures" in an RSS feed. A pod-caster creates a list of music, and/or other sound files (such as recorded poetry, or "talk radio" material) and makes that list available in the RSS 2.0 format. The list can then be obtained by other people using various podcast "retriever" software which read the feed and makes the audio files available to digital audio devices (including, but not limited to iPods) where users may then listen to them at their convenience.See also: RSS
- POP -- (Point of Presence, also Post Office Protocol)
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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.
- Port
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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
- PPP -- (Point to Point Protocol)
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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.
- Protocol
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On the Internet "protocol" usually refers to a set of rules that define an exact format for communication between systems. For example the HTTP protocol defines the format for communication between web browsers and web servers, the IMAP protocol defines the format for communication between IMAP email servers and clients, and the SSL protocol defines a format for encrypted communications over the Internet.
Virtually all Internet protocls are defined in RFC documents.See also: FTP, HTTP, IMAP, POP, PPP, RFC, SLIP, SMTP, SNMP, SSL, TCP/IP, UDP
- Proxy Server
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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
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- RDF -- (Resource Definition Framework)
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A set of rules (a sort of language) for creating descriptions of information, especially information available on the World Wide Web. RDF could be used to describe a collection of books, or artists, or a collection of web pages as in the RSS data format which uses RDF to create machine-readable summaries of web sites.
RDF is also used in XPFE applications to define the relationships between different collections of elements, for example RDF could be used to define the relationship between the data in a database and the way that data is displayed to a user.
- Router
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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
- RSS -- (Rich Site Summary or RDF Site Summary or Real Simple Syndication)
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A commonly used protocol for syndication and sharing of content, originally developed to facilitate the syndication of news articles, now widely used to share the contents of blogs.
RSS is an XML-based summary of a web site, usually used for syndication and other kinds of content-sharing.
There are RSS "feeds" which are sources of RSS information about web sites, and RSS "readers" which read RSS feeds and display their content to users.
RSS is being overtaken by a newer, more complex protocol called Atom. - Back to Index
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- Security Certificate
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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
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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.
Sometimes server software is designed so that additional capabilities can be added to the main program by adding small programs known as servlets.
- SMTP -- (Simple Mail Transfer Protocol)
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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.
- SNMP -- (Simple Network Management Protocol)
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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
- Spam (or Spamming)
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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,
- Spyware
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A somewhat vague term generally referring to software that is secretly installed on a users computer and that monitors use of the computer in some way without the users' knowledge or consent.
Most spyware tries to get the user to view advertising and/or particular web pages. Some spyware also sends information about the user to another machine over the Internet.
Spyware is usually installed without a users' knowledge as part of the installation of other software, especially software such as music sharing software obtained via download. - SSL -- (Secure Socket Layer)
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A protocol designed by Netscape Communications to enable encrypted, authenticated communications across the Internet.
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- TCP/IP -- (Transmission Control Protocol/Internet Protocol)
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This is the suite of 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), IPv4, IPv6, Packet Switching
- Telnet
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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.
- Terabyte
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1000 gigabytes.
See also: Gigabyte
- Terminal
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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
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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.
- TLD -- (Top Level Domain)
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The last (right-hand) part of a complete Domain Name. For example in the domain name www.matisse.net ".net" is the Top Level Domain.
There are a large number of TLD's, for example .biz, .com, .edu, .gov, .info, .int, .mil, .net, .org, and a collection of two-letter TLD's corresponding to the standard two-letter country codes, for example, .us, .ca, .jp, etc.
See also: Domain Name
- Trojan Horse
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A computer program is either hidden inside another program or that masquerades as something it is not in order to trick potential users into running it. For example a program that appears to be a game or image file but in reality performs some other function. The term "Trojan Horse" comes from a possibly mythical ruse of war used by the Greeks sometime between 1500 and 1200 B.C.
A Trojan Horse computer program may spread itself by sending copies of itself from the host computer to other computers, but unlike a virus it will (usually) not infect other programs.
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- UDP -- (User Datagram Protocol)
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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
- Upload
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Transferring data (usually a file) from a the computer you are using to another computer. The opposite of download.
See also: Download
- URI -- (Uniform Resource Identifier)
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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:
telnet://well.sf.ca.us
news:new.newusers.questions
See also: URL
- URL -- (Uniform Resource Locator)
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The term URL is basically synonymous with URI. URI has replaced URL in technical specifications.
See also: URI
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- Virus
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A chunk of computer programming code that makes copies of itself without any concious human intervention. Some viruses do more than simply replicate themselves, they might display messages, install other software or files, delete software of files, etc.
A virus requires the presence of some other program to replicate itself. Typically viruses spread by attaching themselves to programs and in some cases files, for example the file formats for Microsoft word processor and spreadsheet programs allow the inclusion of programs called "macros" which can in some cases be a breeding ground for viruses.
See also: Trojan Horse, Worm
- VOIP -- (Voice Over IP)
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A specification and various technologies used to allow making telephone calls over IP networks, especially the Internet.
Just as modems allow computers to connect to the Internet over regular telephone lines, VOIP technology allows humans to talk over Internet connections.
Costs for VOIP calls can be a lot lower than for traditional telephone calls. Because the IP networks are packet-switched this allows for vastly different ways of handling connections and more efficient use of network resources.See also: Internet (Upper case I), IPv4, IPv6, Modem, Packet Switching
- VPN -- (Virtual Private Network)
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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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- WAN -- (Wide Area Network)
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Any internet or network that covers an area larger than a single building or campus.
See also: internet (Lower case i), LAN
- Web
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Short for "World Wide Web."
See also: WWW
- Web page
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A document designed for viewing in a web browser. Typically written in HTML. A web site is made of one or more web pages.
- Website
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The entire collection of web pages and other information (such as images, sound, and video files, etc.) that are made available through what appears to users as a single web server. Typically all the of pages in a web site share the same basic URL, for example the following URLs are all for pages within the same web site:
http://www.baytherapy.com/
http://www.baytherapy.com/whatis/
http://www.baytherapy.com/teenagers/
The term has a somewhat informal nature since a large organization might have separate "web sites" for each division, but someone might talk informally about the organizations' "web site" when speaking of all of them.
- Wi-Fi -- (Wireless Fidelity)
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A popular term for a form of wireless data communication, basically Wi-Fi is "Wireless Ethernet".
See also: Ethernet
- Worm
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A worm is a virus that does not infect other programs. It makes copies of itself, and infects additional computers (typically by making use of network connections) but does not attach itself to additional programs; however a worm might alter, install, or destroy files and programs.
See also: Trojan Horse, Virus
- WWW -- (World Wide Web)
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World Wide Web (or simply Web for short) is a term 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), more commonly called "web servers", which are the servers that serve web pages to web browsers.
See also: Browser, FTP, HTTP, Internet (Upper case I), Server, URL, Web, Web page
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- XML -- (eXtensible Markup Language)
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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.
- XUL -- (eXtensible User-interface Language)
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A markup language similar to HTML and based on XML.
XUL used to define what the user interface will look like for a particular piece of software. XUL is used to define what buttons, scrollbars, text boxes, and other user-interface items will appear, but it is not used to define how those item will look (e.g. what color they are).
The most widely used example of XUL use is probably in theMozilla web browser, where the entire user interface is defined using the XUL language.
About this glossary:
This Glossary of Internet Terms is licensed under the Creative Commons "Attribution-ShareAlike" license. The original author and copyright holder is Matisse Enzer, and the current version of the Glossary is available at http://www.matisse.net/files/glossary.html.