UpDate - Vol. 13, No. 14, Page TT-4 December 9, 1993 TechTalk What is a network? Network: A set of links among discrete entities. Telephone network (also known as "switching fabric" or "telecom infrastructure"): Cables, wires and switches (including software to control the setting up and tearing down of calls, the transmission of signals across the wires and cables and the management of the network) principally designed to handle voice calls and owned by telephone companies. Computer network: Links among computers that allow each to send to and receive data from other computers in the network. The links can be established using phone lines, radio-based communication or privately owned cables or wires. (Typically, it is economically efficient to use privately owned cables for short distances, such as FidoNet, UUCPnet and BITNET). Public data communications network: A publicly available computer network service operated by telecommunications companies (such as MCImail and Telenet) or by third-party companies (such as CompuServe and Performance Systems International). Internet: The worldwide collection of inter-operable computer networks (public and private) that use the same communications protocols (or "rules of the road"), namely, transmission control protocol/Internet protocol. Reprinted from Educom Review, Vol. 28, No. 5, 1993, September/October. Contact: EDUCOM, 1112 16th St., N.W., Washington, D.C. 20036; (202) 872-4200; e-mail: EDUCOM@BITNIC.EDUCOM.EDU by Laura Breeden and Lawrence Bouman