telnet is a very small and versatile utility that allows for connections on nearly any port. Telnet would allow the admin to connect into remote devices and administer them via a command prompt. In many cases this has been replaced by SSH, as telnet transmits its data in cleartext (like ftp). Telnet can and does however get used in cases where the user is trying to see if a program is listening on a particular port, but they want to keep a low profile or if the connection type pre-dates standard network connectivity methods.