A Useful Glossary of Internet Terms
Microsoft's object development framework. When embedded into HTML documents, ActiveX components are downloaded and executed on the client. ActiveX is currently Windows-only.
(Asymmetric Digital Subscriber Line) -- A variation of Digital Subscriber Line designed for an upstream data flow (client-to-server) which is a fraction of the downstream data flow (server-to-client). Typically the upstream data flow is measured in kilobits per second while the downstream data flow is measured in megabits per second (e.g. 6 megabits per second over standard phone lines).
A transmission mode in which data is represented by a continuously varying electrical signal.
(Anonymous File Transfer Protocol) -- An interactive service provided by many Internet hosts allowing any user to transfer documents, files, programs, and other archived data using File Transfer Protocol.
Small Java programs that run on Web clients.
A tool for locating files that are publicly available by anonymous FTP.
(Advanced Research Projects Agency Network) -- The precursor to the Internet. Developed in the late 60s and early 70s by the US Department of Defense, it served as the basis for early networking research, as well as a central backbone during the development of the Internet.
(American Standard Code for Information Interchange) -- A seven-bit character set used to exchange alphanumeric information between computer systems.
(Asynchronous Transfer Mode) -- An international networking standard in which multiple service types (such as voice, video, or data) are conveyed in fixed-length (53-byte) cells.
An application that supports document creation; can refer to anything from an HTML helper application to an integrated publishing environment that allows the user to create pages for the World Wide Web.
A high-speed line or series of connections that forms a major pathway within a network.
Measure of the information capacity of a transmission channel. Strictly speaking, bandwidth is the difference, expressed in hertz (Hz), between the highest and lowest frequencies of the channel.
In the world of internet hosting, bandwidth usually refers to the amount of information that can be transferred to or from your site over a specified time period.
In common usage the baud rate of a modem is how many bits it 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).
(Bulletin Board System) -- Computer system used as an information source and message switching system for a particular interest group. A place that allows people to carry on discussions, upload and download files, and make announcements.
(BINary HEXadecimal) -- A format commonly used in sending large files and images over the Internet.
Automated methods that measure physical characteristics or personal traits, such as hand profiles or voice prints, to verify a person's identity. Uses include security access and fraud prevention.
(Binary DigIT) -- The units -- 0 or 1 -- used in the binary numbering system.
(Bits Per Second) -- A common measurement of the speed at which data is moved from one place to another.
A connection to the Internet that works at high speeds because of its greater bandwidth.
A program that allows a person to read hypertext and view graphical images. Provides a means of viewing the contents of Web pages and navigating from one Web page or Web server to another.
A series of bits of data, usually 8 or 16 bits, that are handled as a unit.
The generic name given to services which use fibre optic cable buried underground to carry telephone, television and broadband to your home.
A small fast memory holding recently-accessed data, designed to speed up subsequent access to the same data. Most often applied to processor-memory access but also used for a local copy of data accessible over a network etc.
Used to copy someone on an email list.
European Laboratory for Particle Physics located near Geneva, Switzerland. Birthplace of the World Wide Web.
An entity that attests to the identity of a person or an organization. A Certificate Authority might be an external company such as VeriSign that offers certificate services or they might be an internal organization such as a corporate MIS department. The Certificate Authority's chief function is to verify the identity of entities and issue digital certificates attesting to that identity.
(Common Gateway Interface) -- A standard for running external programs from a World-Wide Web HTTP server. CGI specifies how to pass arguments to the executing program as part of the HTTP request. It also defines a set of environment variables. Commonly, the program will generate some HTML which will be passed back to the browser, but it can also request URL redirection.
The most common name of a directory on a Web server in which CGI programs are stored.
A software program that is used to contact and obtain data from a server software program on another computer, often across a great distance. Each client 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.
Contention means that you share your bandwidth with a number of other users. This means that the quality and speed of connection is dependent on the number of users online at any given time. For business ADSL use, the contention ratio is likely to be around 20:1. In other words, up to 19 other users share your bandwidth. For cable modem uses, the contention ratio could be as high as 50:1. In other words, up to 49 other users share your bandwidth.
A mechanism for storing persistent information on a Web client that can be used by a Web server.
Term originated by author William Gibson in his novel Neuromancer in the early 1980s. It describes a new world, created by intersecting computer networks.
A self-contained, independent entity of data carrying sufficient information to be routed from the source to the destination computer without reliance on earlier exchanges between this source and destination computer and the transporting network.
A dial-up connection uses a telephone line to connect to the Internet. A modem is used to turn data into audio signals so that it can literally 'dial' the number of your internet service provider (ISP) and communicate with their computers.
(Domain Name Service) -- A service that supports the use of a name such as www.company.com rather than a cryptic IP address such as 204.147.276.50.
Exclusive name that identifies an Internet site.
The electronic transfer of information from one source to another.
(Digital Subscriber Line) A digital telecommunications protocol for use over existing copper telephone lines, as opposed to optical fiber. Also, High-Speed Digital Subscriber Line (HDSL).
A small town in Gloucestershire, on the edge of the Cotswolds
Also, the name of Harry Potter's adoptive family.
HTML is the language that describes how text and images are displayed on a Web page. Dynamic HTML presents richly formatted pages that lets users interact with the content on those pages without having to download additional content from the server. This means that a page can respond immediately to user actions, such as a mouse click, without having to retrieve an entire new page from the server. Dynamic HTML gives developers precise control over formatting, fonts, and layout, and provides a dramatically enhanced object model for making pages interactive.
(Electronic Mail) -- Messages, usually text, sent from one person to another via a computer network.
Process of converting information into a secure form that cannot be read by others until it is decoded.
Institute of Electrical and Electronic Engineers (IEEE) standard data link protocol that specifies how data is placed on and retrieved from a common transmission medium. Forms the underlying transport vehicle used by several upper-level protocols, including TCP/IP and XNS. See CSMA/CD (Carrier Sense Multiple Access/Collision Detect) for a description of Ethernet's media-access method.
Use of Internet-oriented standards, technologies, and products between different companies, such as TCP/IP as the transport, HTTP servers for presenting documents, and SMTP and POP servers for mail. Typically used to increase productivity and function as a collaborative processing infrastructure between partner companies. They increase productivity and function as a collaborative processing infrastructure.
(Frequently Asked Questions) -- Documents that list and answer common questions on a particular subject.
A 100-Mbps technology based on the 10BASE-T Ethernet CSMA/CD network access method.
(Fiber Distributed Data Interface) -- LAN technology, defined by American National Standards Institute (ANSI) X3T9.5, that specifies an 100- Mbps token-passing network using fiber-optic cable.
An Internet software tool for locating people on other Internet sites.
A router or access server that serves as a buffer between connected networks or interfaces. Uses access lists, protocol filters, and other methods, to safeguard network resources.
An angry response to an electronic posting, usually in a newsgroup.
A packet-switching wide-area technology for interconnecting LANs at high speeds. Defines the interface between user equipment and a WAN, but does not define internal operation of the network or the interfaces or protocols used within the WAN itself. For this reason, the term "frame relay cloud" is often used to describe the internal operation of a WAN that has a frame relay interface.
(File Transfer Protocol) -- An Internet application and protocol commonly used to move files between two Internet sites, servers, or workstations.
Device that can interconnect networks with different, incompatible communications protocols. The gateway performs a layer-7 protocol-conversion to translate one set of protocols to another (for example, from TCP/IP to SNA or from TCP/IP to X.25). A gateway operates at Open Systems Interconnection (OSI) layers up through the Session Layer.
(Graphics Interchange Format) -- A format developed in the mid-1980s by CompuServe for use in photo-quality graphics images. Now commonly used in online Web pages.
1000 megabits [or 1024 megabits depending on who you ask!]
1000 megabytes [see above!]
(Global Internet Exchange) -- The process and equipment by which Internet traffic between backbone providers is concentrated and exchanged. There are several physical GIX locations, the largest being in Washington, D.C. There is also a GIX center in Sweden.
A program on the Internet that organizes information into menus and lets users jump from one point on the "net" to another.
Applications that let network users work collaboratively on common files.
A visitor's first point of entry to a Web site; typically features a site index.
A domain name that has an IP address record associated with it; any computer system connected to the Internet.
A connection to a document or other file on the Internet. Generally appears as a highlighted word or image for selection on the browser interface.
(HyperText Markup Language) -- A computer language for describing a page of information for display on the World Wide Web.
(HyperText Transport Protocol) -- The protocol for exchanging HTML pages over the World Wide Web.
A device used to interconnect other LAN devices, usually in a star topology.
Text in one document that is linked electronically to text in another document or another part of the same document.
The global collection of interconnected networks that all use the TCP/IP protocol.
Use of Internet-oriented standards, technologies, and products to enhance productivity and to function as a collaborative processing infrastructure within an enterprise.
(Internet Protocol) -- The packet-switching protocol for network communications between Internet hosts.
Method used by hackers to break into computers over the Internet using the IP address, the computer's Internet ID.
IPSec is an emerging standard to add security services to the IP protocol. It provides robust security, encompassing user authentication, privacy, and data integrity.
Formal designation for the next generation Internet Protocol being developed within the Internet Engineering Task Force (IETF), which will enable continued growth of the Internet. Designed to alleviate anticipated shortages of IP addresses and router overload, as well as provide for autoconfiguration, network layer security and quality of service capabilities unavailable in IPv4. Also known as IPng, where the "ng" represents "next generation."
(Internet Relay Chat) -- The Internet protocol that defines real-time communications between a server and a group of clients over the Internet.
(Integrated Services Digital Network) -- International digital communications protocol, offered by telephone companies, that permits telephone networks to carry data, voice, and other traffic.
(International Standards Organization) -- Organization responsible for a wide range of standards, including many relevant to networking. Developed the Open Systems Interconnection (OSI) reference model, widely used in networking today.
(Internet Service Provider) -- An entity that provides public access to the Internet.
A portable, secure programming environment that allows developers to create applications for HTML pages.
An easy-to-use, object-oriented scripting language designed for creating dynamic applications that link objects and resources residing on Internet clients and servers.
(Joint Photographic Experts Group) -- A compressed file format for digital images.
A thousand [or 1024] bits.
A thousand [or 1024] bytes.
(Layer 2 Tunneling Protocol) -- An IEEE standard for tunneling that includes the ability to terminate tunnels at either the NSP or enterprise network, to apply access policies at the firewall, and to perform tunnel switching.
(Local Area Network) -- A set of computers connected together to share common resources, such as printers. Computers connected on a LAN have the ability to share applications or files from a local file server and are able to make connections to other LANs or the Internet via routers.
(Lightweight Directory Access Protocol) -- An open standard for storing and retrieving names, addresses, email, phone numbers, and other information from an online directory. Used to build online directories on enterprise networks, as well as Internet-based online directories.
A transmission line reserved by a communications carrier for the private use of a customer.
A sequence of numbers and letters that uniquely identify a user for access to computer resources.
A million bits.
A million bytes. A thousand kilobytes.
Software that operates between the application and the control program, providing a single programming interface for an application.
(Multipurpose Internet Mail Extensions) -- A standard that allows users to send and receive electronic mail messages with multimedia content over the Internet.
Generally speaking, "to mirror" is to maintain an exact copy of something. The most common use of the term on the Internet refers to "mirror sites" which are Web FTP sites that maintain exact copies of material originated at another location, usually in order to provide more widespread access to the resource. Another common use of the term "mirror" refers to an arrangement where information is written to more than one hard disk simultaneously, so that if one disk fails, the computer keeps on working without losing data.
(MOdulator, DEModulator) -- A device used to convert serial digital data to a signal for transmission over a telephone network.
Early public-domain Web browser, developed at the National Center for Supercomputing Applications (NCSA).
The process of moving from one web site to another using a web browser, usually accomplished by following links embedded in web pages.
A light-hearted term referring to a citizen of the Internet community.
A communications system that links two or more computers. May be as simple as a cable strung between two computers a few feet apart, or as complex as hundreds of thousands of computers around the world linked through fiber optic cables, phones lines, and satellites.
An area where people can discuss common topics by leaving postings, as on a bulletin board, that others can read when they log on. "Newsgroups" generally refer to discussions on USENET, which most people access via the Internet.
A point of interconnection to a network. Any station, terminal, or communications processor in a computer network.
Type of data transfer that occupies a communication link only during the time of actual data transmission. Messages are split into packets and reassembled at the receiving end of the communication link.
A code used to gain access to a secured system.
(Practical Extraction and Report Language) -- An interpreted language that originated with UNIX. On many Web servers, Perl is used as an easy programming language suitable for writing simple CGI scripts; these scripts are called by HTML pages and executed on the server.
(Pretty Good Privacy) -- A high-security cryptographic software application that allows people to exchange messages with both privacy and authentication.
Small applications that add new functionality to a Web browser. For example, an audio plug-in allows a browser user to listen to audio files on a Web page or in an email message.
(Point of Presence) -- Physical access point to a long distance carrier or Internet service provider network.
The Internet standard for mail servers.
An interface on a networking device. A number that identifies a particular Internet application.
(Point to Point Protocol) -- A protocol that allows a computer to use the Internet protocols (TCP/IP) with a standard phone line and a high-speed modem.
(Point to Point Tunneling Protocol) - Protocol used to create LAN-to-LAN tunnels between Windows NT servers that have installed the PPTP protocol. PPTP wraps and encrypts IP packets and sends them to a destination server. This provides secure tunneling between sites from within NT, without extra equipment or changes to the network. This protocol is used to provide security for data when accessing a company network remotely, through the Internet.
A formal set of rules and conventions that govern how devices on a network exchange information.
An entity that caches frequently accessed documents to conserve network bandwidth and reduce network response times for users.
(Public Switched Telephone Network) -- The worldwide public telephone systems.
Term used to describe remote user access via a telecommunications system to the company network.
(Request For Comments) A Document series used as the primary means for communicating information about the Internet.
A special-purpose, network layer device that manages the connection between two or more networks. The device makes decisions about which of several paths the network (or Internet) traffic will follow.
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.
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. A single server machine could have several different server software packages running on it, thus providing many different servers to clients on the network.
(Serial Line Internet Protocol) -- A protocol that allows a computer to use the Internet protocols (TCP/IP) with a standard phone line and a high-speed modem.
(Switched Multimegabit Data Service) -- A high-speed, fiber-based LAN interconnection service that allows users to use a public network service to allocate wide area bandwidth as it is needed.
(Simple Mail Transport Protocol) -- The Internet standard protocol for transferring electronic mail messages from one computer to another. SMTP specifies how two mail systems interface and the format of control messages they exchange to transfer mail.
(Simple Network Management Protocol) --A network management protocol for the exchange of information among network components. Network management applications use this information to provide network managers with views into network traffic for device configuration, troubleshooting, and network planning.
The sending of unsolicited email to a large number of people.
(Structured Query Language) A standard language for querying relational and other databases.
(Secure Sockets Layer) -- The encrypted security protocol implemented by Netscape in its browsers and servers to provide secure transactions over the Web.
Digital wide area communications circuit provided by telephone carriers for voice and data transmission (1.544 Mbps in U.S.; 2.054 Mbps in Europe); may be divided in 24 separate 64 Kb channels.
Digital wide area communications circuit standard (44.736 Mbps in the U.S.; 34.368 Mbps in Europe).
(Transmission Control Protocol/Internet Protocol) -- A suite of protocols that performs the transfer of data across internetworks, including the Internet.
The command and program used to login from one Internet site to another.
1000 [or 1024] gigabytes.
A chain of articles or messages posted in response to an originating article or message.
Local area network architecture that connects stations in a closed loop and grants permission to send by circulating a token.
A multi-user operating system developed by AT&T Bell Labs and currently popular as an application server operating system.
(Universal Resource Locator) -- Uniquely identifies a file available on the World Wide Web.
A worldwide system of discussion groups, with comments passed among hundreds of thousands of machines.
(UNIX to UNIX Encoding) -- A program that encodes binary information, such as graphic images or document files, so that they can be sent across the Internet via e-mail.
(Very Easy Rodent Oriented Net-wide Index to Computerized Archives) -- Developed at the University of Nevada, Veronica is a constantly updated database of the names of almost every menu item on thousands of gopher servers. The Veronica database can be searched from most major gopher menus.
Code written to infect computers with destructive macros or applications.
(Virtual Private Network) -- Provides a mechanism for forwarding dial-up data packets over the Internet in such a way that end users appear as if connected directly to their destination or home network. This is done using a technique called tunneling. Tunnels represent virtual, dedicated connections between the dial-up access point and a destination point somewhere on the network. The destination is usually the point at which a corporation or an enterprise is connected to the Internet.
(Virtual Reality Modeling Language) A way to specify a 3D scene for viewing over the World Wide Web.
(Wide Area Information Servers) -- Sophisticated indexing and search tool for full-text databases.
(Wide Area Network) -- Computer network serving a wide geographic area.
Web sites are collections of electronic "pages". Each Web page is an HTML (HyperText Markup Language) document that may contain text, images, or media objects.
(What You See Is What You Get) -- Refers to authoring systems that display a document as it will appear on screen, even as the user is creating or editing it.
(World Wide Web) -- A collection of Internet host systems that provide information on the Internet, usually in the form of hypermedia.
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