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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Acceptable Use Policy -- (abbreviation: AUP)
A formal set of rules that governs how a network may be used. For example, the original NSFnet Acceptable Use Policy forbade non-research use by commercial organizations.
AUPs sometimes restrict the type of material that can be made publicly available; many AUPs ban the transmission of pornographic material.
The enforcement of AUPs has historically been very uneven. This was true of the NSFnet AUP: its limitations on commercial activity were so widely ignored that it was finally abandoned in 1994, enabling the development of today's commercial Internet. See also Netiquette, Terms of Service.

access number -- The telephone number used by a subscriber to dial into an Internet Service Provider or online service.

ACK -- 1. Acknowledge. Used to confirm one's presence. An appropriate response to ping.
2. When one computer sends a block of data to another over a network, the second computer sends an acknowledgment code back to indicate that the transfer was successful. If there were errors detected in the transmission, the second computer would send a negative acknowledgment (NAK).

Active X -- A software technology developed by Microsoft that allows programmed capabilities or content to be delivered to Windows-based personal computers via the World Wide Web. Active X is notable for a complete lack of security controls; computer security experts discourage its use over the Internet.

address -- There are three types of addresses in common use on the Internet: email addresses, IP addresses, and Uniform Resource Locators. See also email address, IP address, Uniform Resource Locator.

address book -- A feature of some email applications that stores names and email addresses in an accessible format.

AFK -- Abbreviation for Away From Keyboard.

agent -- A software process empowered to transparently act for or represent a user by completing transactions, seeking information of specific interest, or communicating with other users and agents. The Firefly online service is a good example of agent technology at work, http://www.firefly.com

AI -- See artificial intelligence.

alt -- 1. A top-level category of "alternative" USENET newsgroups. These unmoderated newsgroups can be started by anyone with the time, equipment, and expertise. The alt hierarchy covers perhaps the widest variety of topics ranging from the informative to the bizarre, and from the politically radical to the explicitly sexual.
2. The Alt key on the keyboard of IBM PC compatibles, typically used in conjunction with other keys.

AltaVista -- An Internet search engine at http://www.altavista.digital.com

America Online -- The leading commercial online service that serves as an entry point into cyberspace for millions of network newcomers.

anonymous FTP -- A service that allows free public access to archived documents, files, and programs via the File Transfer Protocol (FTP). It's not necessary to have a user ID and password when logging into an anonymous FTP site. The user ID "anonymous" bypasses local security checks; often email addresses serve as courtesy passwords. See also File Transfer Protocol.

API -- See Application Program Interface.

applet -- A Java program which is designed to run only on a web page. To use an applet on a web page, you would specify the name of the applet and the size (length and width--in pixels) that the applet can utilize. When the web page is accessed, the browser downloads the applet from a server and runs it on the user's machine (the client). Applets differ from applications in that they are governed by a strict security protocol. For example, even though applets run on the client, they can not read or write data onto the client's machine. Additionally, applets are further restricted so that they can only read and write data from the same domain that they are served from. See also Java.
Here is the code for a Java applet version of "Hello Word!":
import java.awt.Graphics;
public class HelloWorldApplet extends java.applet.Applet {
public void paint(Graphics g) {
g.drawString("Hello world!", 5, 25);
}
}

application -- A self-contained program that performs a well-defined set of tasks under user control, as opposed to a system program. Web browsers, mail readers, and FTP clients are examples of applications commonly used on the Internet.

Application Program Interface -- (abbreviation: API)
A document for programmers that provides the technical specifications for interfacing with an application from another program.

Archie -- A database service that automatically gathers, indexes, and catalogues files on Internet servers. The initial implementation of Archie provided an indexed directory of filenames from all anonymous FTP archives on the Internet. Later versions provide other collections of information. Archie was developed by McGill School of Computer Science.

archive site -- A server that provides access to an organized collection of files available to the public.

ARPANET -- Forerunner of the Internet created by the United States military during the cold war. ARPANET was designed by its founders to be a military command and control center that could withstand nuclear attack. ARPANET's founders designed it so that authority was distributed over a large number of geographically dispersed computers. This concept of a computer network with distributed authority is the basis of the Internet. Theoretically, if 90% of the Internet were destroyed by nuclear attack, the remaining servers would be able to continue on--assuming that all life on Earth were not obliterated. Over time the defense-oriented purpose of the Internet was broadened to include research and development, universities and education, and recently, commerce.

artificial intelligence -- (abbreviation: AI)
A branch of computer science that studies how to endow computers with capabilities of human intelligence. For example, speech recognition is a problem being worked on by AI scientists.

ASCII -- Acronym for American Standard Code for Information Interchange, pronounced "ass-key". ASCII is a code that assigns a number to each key on the keyboard. ASCII text does not include special formatting features and therefore can be exchanged and read by most computer systems.

attached file -- A file that is embedded into an email message.

AUP -- See Acceptable Use Policy.

authentication -- The verification of the identity of a person or process.


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