SSH (Secure SHell) is a program to let you login securely to
another computer on the Internet in order to use typed commands.
It encrypts your username, password, and your session commands
and output. For some applications this is much faster and
simpler than using a Web interface. You must have a valid,
authorised username and password for the remote machine.
Telnet is an earlier, insecure form of a similar service. SSH
is now used instead of Telnet because Telnet transmits all data
unencrypted, which is a security risk.
Most computers that you can log into this way
use the Unix operating system or one of its derivatives (Linux
and recent Apple Mac systems are all Unix-based). You will need
to know what commands to type if you want to use such
systems. There is a brief summary of some of the common commands