4. Terminal emulator
A terminal emulator, terminal application, term, or tty for
short, is a program that emulates a “dumb” video terminal
within some other display architecture.
5. NVT
The telnet protocol assumes that each end of
the connection-the client and the sever
- is a Network Virtual Terminal..
6. IP address
IP address is also sent ,so that
information can be routed back to client.