Telnet is a terminal emulation program which is mainly used for the Internet. This emulation program runs on your personal computer and the way it functions is that it connects to a servers and helps you connect to the internet.
The Telnet program is what informatics calls it a meta-program for its abilities to function are behind the whole process that we experience as users. Same as watching a theater play, you as an observer never can know what is going on behind the stage and how everything happened.
It is the same way this meta-program works. It works behind the curtains and allows you to manipulate your server on the network as well as giving you the command to communicate with other servers.
This is provided through the server console which is used to perform these actions and commands. Of course, to use a Telnet program you must create an account with a valid username and pass code.
The Telnet program is often used by people to remotely control web-networking and other web-sites. Also bear in mind that manipulating with another computer on the network is only possible if they also use the telnet protocol.