Telnet provides a remote logon
capability, which enables a user at a terminal or personal computer to logon
to a remote computer and function as if directly connected to that computer.
The protocol was designed to work with simple scroll-mode terminals. Telnet
is actually implemented in two modules: User TELNET interacts with the
terminal I/O module to communicate with a local terminal. It converts the
characteristics of real terminals to the network standard, and vice versa.
Server TELNET interacts with an application, acting as a surrogate terminal
handler so that remote terminals appear as local to the application.
Terminal traffic between user and server TELNET is carried on a TCP
connection. The TELNET application provided a common-denominator terminal.
If software was written for each type of computer to support the "TELNET
terminal," one terminal could interact with all computer types.