Game Development Dictionary
Telnet is a protocol that allows you to connect to remote computers (called hosts) over a TCP/IP network (such as the Internet). You use software called a telnet client on your computer to make a connection; there is a telnet server on the remote host, which the telnet client negotiates with to establish a connection. Once connected, the client becomes a virtual terminal, and allows you to communicate with the host computer from your computer. In most cases, you'll be asked to log into the remote system. This usually requires an account on that system. Occasionally you can log in as guest or public without having an account. Telnet clients are available for all major operating systems.