Yes, as Mr Baruti has said, telnet allows you to remotely emulate a machine. To be specific, telnet is a protocol standing for Terminal Emulation. The 2 most common telnet softwares are HyperTerminal and Telnet in windows. This feature emulates another machne using the TCP/IP protocol suit as the means of connection.
Telnet was one of the first protocols to be developed during the early stages of the ARPANET that later became the Internet. telnet allows you to login to another Internet location to gain access to databases, library catalogs, and interactive environments.
For those od us that are familiar with the Open Systems Interconnect layers (OSI), telnet works at the session to application layers (5-7). Is also used for hacking!
I'm sure u can find more info on telnet on the internet. Feel free to ask for more info pls.