Terminal Servers

Many installations no longer connect terminals directly to
computers. Instead they connect them to terminal servers. A terminal
server is simply a small computer that only knows how to run telnet
(or some other protocol to do remote login). If your terminal is
connected to one of these, you simply type the name of a computer, and
you are connected to it. Generally it is possible to have active
connections to more than one computer at the same time. The terminal
server will have provisions to switch between connections rapidly, and
to notify you when output is waiting for another connection. (Terminal
 servers use the telnet protocol, already mentioned. However any real
terminal server will also have to support name service and a number of
other protocols.)