Association for Computer Machinery: A group established in 1947 to promote professional development and research on computers.

Artificial Intelligence: The branch of computer science which deals with the simulation of human intelligence by computer systems.

American National Standards Institute: A group that defines U.S. standards for the information processing industry. ANSI participates in defining network protocol standards.

Address Resolution Protocol: An Internet protocol which runs on Ethernets and Token Rings and maps Internet addresses to MAC addresses.

Advanced Research Projects Agency Network: A pioneering long haul network funded by ARPA. It served as the basis for early networking research as well as a central backbone during the development of the Internet. The ARPANET consisted of individual packet switching computers interconnected by leased lines.

American Standard Code for Information Interchange.

bit - binary digit: The smallest amount of information which may be stored in a computer.

Bolt, Beranek, and Newman, Inc.: The Cambridge, MA, company responsible for development, operation and monitoring of the ARPANET, and later, the Internet core gateway system, the CSNET Coordination and Information Center (CIC), and NSFnet Network Service Center (NNSC).

bits per second: A measure of data transmission speed.

A network in which hosts are connected to networks with varying characteristics, and the networks are interconnected by gateways (routers). The Internet is an example of a catenet.