(tel net) (n.) Telnet is a terminal emulation program for TCP/IP networks such as the Internet. The Telnet program runs on your computer and connects your PC to a server on the network. You can then enter commands through the Telnet program and they will be executed as if you were entering them directly on the server console. This enables you to control the server and communicate with other servers on the network. To start a Telnet session, you must log in to a server by entering a valid username and password. Telnet is a common way to remotely control Web servers.
The Telnet Protocol
The Telnet protocol is designed to provide a bi-directional, eight-bit byte oriented communications facility to allow for a a standard method of interfacing terminal devices and processes. Additional information on the Telnet protocol specification can be found here.