Terms and Definitions

world wide web (WWW)

A system of Internet servers that support specially formatted documents. The documents are formatted in a markup language called HTML (HyperText Markup Language) that supports links to other documents, as well as graphics, audio, and video files. This means you can jump from one document to another simply by clicking on hot spots. Not all Internet servers are part of the World Wide Web.

HTML

Short for HyperText Markup Language, the authoring language used to create documents on the World Wide Web. HTML is similar to SGML, although it is not a strict subset. HTML defines the structure and layout of a Web document by using a variety of tags and attributes. The correct structure for an HTML document starts with (enter here what document is about) and ends with . All the information you'd like to include in your Web page fits in between the and tags.

Hypertext

machine-readable text that is not sequential but is organized so that related items of information are connected; "Let me introduce the word hypertext to mean a body of written or pictorial material interconnected in such a complex way that it could not conveniently be presented or represented on paper"--Ted Nelson

Domain name system (DMS)

Short for Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4. The DNS system is, in fact, its own network. If one DNS server doesn't know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.

Internet Access Provider

Internet access provider

Dumb Terminal

A display terminal that provides keyboard input and screen output and no data processing capability. Dumb terminals flourished in the days of minicomputers and mainframes.

Wireless Network

A system that transmits and receives radio signals over the air. The term generally refers to Wi-Fi local area networks (LANs) as well as the optional data services provided by the nationwide cellular carriers (WANs)

Modem

MOdulator-DEModulator) Until the late 1990s, the term referred to a device that allows a computer or terminal to transmit data over a standard dial-up telephone line. Since the advent of cable and DSL connections, the term may also refer to high-speed broadband modems

FTP

(File Transfer Protocol) A protocol used to transfer files over a TCP/IP network (Internet, Unix, etc.). For example, after developing the HTML pages for a Web site on a local machine, they are typically uploaded to the Web server using FTP.

NFS

(Network File System) The file sharing protocol in a Unix network. This de facto Unix standard, which is widely known as a "distributed file system," was developed by Sun. The name is somewhat misleading because NFS is not a disk file system that reads and writes the disk sectors, but enables the operating system to view files on computers in the network as if they were local

Gopher

A protocol for searching file names and resources on the Internet that presents hierarchical menus to the user. As users select options, they are moved to different Gopher servers. Where links have been established, Usenet news and other information can be read directly from Gopher.

Browser

A program that lets you look through a collection of data.

E-Mail

(Electronic-MAIL) The transmission of text messages from sender to recipient. E-mail messages can also be formatted with graphics like a brochure or Web page, an enhancement that many users like, but that creates more spam and a security risk

Applet

A small application, such as a utility program or limited-function spreadsheet or word processor. Java programs that are run from the browser are always known as applets.

ASCII

American Standard Code for Information Interchange) Pronounced "ask-ee," it is the built-in binary code for representing characters in all computers except IBM mainframes, which use the EBCDIC coding system. ASCII was originally developed for communications and uses only seven bits per character, providing 128 combinations that include upper and lower case alphabetic letters, the numeric digits and special symbols such as the $ and %. The first 32 characters are set aside for communications and printer control

Binary

Meaning two. The principle behind digital computers. All input to the computer is converted into binary numbers made up of the two digits 0 and 1 (bits). For example, when you press the "A" key on your keyboard, the keyboard circuit generates and transfers the number 01000001 to the computer's memory as a series of pulses with different voltages. The bits are stored as charged and uncharged memory cells or as microscopic magnets on disk and tape. Display screens and printers convert the binary numbers into visual characters.

Bit

(BInary digiT) The smallest element of computer storage. It is a single digit in a binary number (0 or 1). The bit is physically a transistor or capacitor in a memory cell, a magnetic domain on disk or tape, a reflective spot on optical media or a high or low voltage pulsing through a circuit.

Byte

(BinarY TablE) The common unit of computer storage from desktop computer to mainframe. It is made up of eight binary digits (bits). A ninth bit may be used in the memory circuits as a parity bit for error checking. The term was originally coined to mean the smallest addressable group of bits in a computer, which has not always been eight.

Client

1) A user's computer, which is generally a Windows, Mac or Linux desktop or laptop. The term implies that the client machine is connected to a network. Contrast with server. See client application, client download, client/server, thin client and fat client.

Cookie

1) A small amount of data sent back to the requesting party by the recipient. Also called a "magic cookie," it provides information about the transaction, such as an ID or session number, which may be required later either by the recipient or a third party. This is the same concept as definition #2 below, but not specific to the Web.

Cyberspace

Coined by William Gibson in his 1984 novel "Neuromancer," it is a futuristic computer network that people use by plugging their minds into it! The term now refers to the Internet or to the online or digital world in general.

DNS

Domain Name System) A system for converting host names and domain names into IP addresses on the Internet or on local networks that use the TCP/IP protocol. For example, when a Web site address is given to the DNS either by typing a URL in a browser or behind the scenes from one application to another, DNS servers return the IP address of the server associated with that name. In this hypothetical example, WWW.COMPANY.COM would be converted into the IP address 204.0.8.51. Without DNS, you would have to type the four numbers and dots into your browser to retrieve the Web site, which of course, you can do. Try finding the IP of a favorite Web site and type in the dotted number instead of the domain name!

Domain name

he term may refer to any type of domain within the computer field, since there are several types of domains (see domain). However, today, it often refers to the address of an Internet site.

Download

To transmit a file over a network. In a communications session, "download" and "upload" imply a big/little scenario, in which data are being downloaded from the "big" server into the user's "little" computer. Uploading sends data from the little computer to the big computer. The time it takes to download data depends on file size and network speed. Via analog dial-up modems, Web pages take a few seconds, but a 20MB video file can take an hour. Downloading over DSL or cable can be from 15 to 400 times faster. Downloading from a file server on a local area network (LAN) can be even faster.

DSL Fire Wall

Flame

To communicate emotionally via e-mail. Just as people might differ about what is polite behavior and what is not, whether an e-mail message is flaming is also in the eye of the beholder. Vulgar cursing would definitely be flaming, however

GIF

(Graphics Interchange Format) A popular bitmapped graphics file format developed by CompuServe. Pronounced "giff" with a hard "g" by most Mac users and "jiff" by PC users, GIFs are widely used on the Web because the format uses its own form of compression.

Gigabyte

One billion bytes. Also GB, Gbyte and G-byte.

Hit

A successful match.

Homepage

The first page retrieved when accessing a Web site or the first screen displayed when a PDA or smartphone is started. It provides the main menu and starting point for the rest of the content on the site or device.

Intranet

n inhouse Web site on the company's local area network (LAN) that serves employees only, and almost every medium to large company has an intranet. Although intranet pages may have links to Web sites on the Internet, the intranet is not exposed to, or is accessed by, the general public. It provides a standard way to publish company policy, news, schedules, medical and insurance forms and training manuals. The intranet is also a venue for publishing blogs, wikis and social activities such as sports and exercise schedules.

Internet

The global network of networks (see definition #1 above), composed of hundreds of millions of computers in more than 100 countries. Originally developed for the U.S. military, it became widely used for academic and commercial research, with access to unpublished data and journals on many subjects. Today, the "Net" is the world's largest source of information on every subject known to humankind and the world's largest mail-order catalog. By 2005, the Internet surpassed one billion users.

Java

An object-oriented programming language that is platform independent. Developed by Sun, Java is widely used on the Web for both client and server processing. Modeled after C++ and designed to run in limited memory, Java added programming enhancements such as "garbage collection," which automatically frees unused memory.

LAN

(Local Area Network) A communications network that serves users within a confined geographical area. The "clients" are the user's workstations typically running Windows, although Mac and Linux clients are also used. The "servers" hold programs and data that are shared by the clients. Servers come in a wide range of sizes from Intel-based servers to mainframes. Printers can also be connected to the network and shared

Listserv

ailing list management software from L-Soft international, Inc., Landover, MD (www.lsoft.com) that runs on Windows, Mac, OpenVMS, VM (mainframe) and various Unix machines. LISTSERV scans e-mail messages for the words "subscribe" and "unsubscribe" to automatically update the list. Virus protection is also provided. The LISTSERV program originated in France in 1986 by engineering student Eric Thomas, who went on to found the L-Soft company in 1994

Login

Signing in and gaining access to a network server, Web server or other computer system. The process (the noun) is a "login" or "logon," while the act of doing it (the verb) is to "log in" or to "log on." In practice, "login" is used as a verb as well.

Megabyte

One million bytes, or more precisely 1,048,576 bytes. Also MB, Mbyte and M-byte.

Network

(1) A system that transmits any combination of voice, video and/or data between users. The network includes the network operating system in the client and server machines, the cables connecting them and all supporting hardware in between such as bridges, routers and switches. In wireless systems, antennas and towers are also part of the network.

Password

A secret word or code used to serve as a security measure against unauthorized access to data. It is normally managed by the operating system or DBMS. However, the computer can only verify the legitimacy of the password, not the legitimacy of the user.

Plugin

Software that is installed as an add-on to an application in order to enhance its capability. For example, plug-ins are widely used in image editing programs such as Photoshop to add some special effect. Plug-ins are added to Web browsers to enable them to support different types of content (audio, video, etc.). The term is widely used for software, but can also refer to a plug-in module for hardware.

Protocol

The format and procedure that governs the transmitting and receiving of data. The term comes from the Greek "protokollon," which was the cover page to a manuscript that provided a description of the contents.

Search Engine

Software that searches for data based on some criteria. Although search engines have been around for decades, they were brought to the forefront after the Web exploded onto the scene. Every Web search engine site uses a search engine that it has either developed itself or has purchased from a third party. Search engines can differ dramatically in the way they find and index the material on the Web, and the way they search the indexes from the user's query.

Spam

E-mail that is not requested. Also known as "unsolicited commercial e-mail" (UCE), "unsolicited bulk e-mail" (UBE), "gray mail" and just plain "junk mail," the term is both a noun (the e-mail message) and a verb (to send it). Spam is mostly used to advertise products and sometimes to broadcast some political or social commentary

Trojan Horse

Upload

To send data from a user's machine to a server. For more details,

Virus

Software used to infect a computer. After the virus code is written, it is buried within an existing program. Once that program is executed, the virus code is activated and attaches copies of itself to other programs in the system. Infected programs copy the virus to other programs.

Website

A presence on the World Wide Web. To qualify as a bona fide Web site, it must be available on the Internet around the clock. A Web site is a collection of Web pages, which are documents coded in HTML that are linked to each other and very often to pages on other Web sites. A Web site is run (hosted) on a Web server by the site's owner or by a third-party Internet service provider (ISP).

Worm

1) A destructive program that replicates itself throughout a single computer or across a network, both wired and wireless. It can do damage by sheer reproduction, consuming internal disk and memory resources within a single computer or by exhausting network bandwidth. It can also deposit a Trojan that turns a computer into a zombie for spam and other malicious purposes. Very often, the terms "worm" and "virus" are used synonymously; however, worm implies an automatic method for reproducing itself in other computers.