Source : Free On-Line Dictionary of Computing

Secure Shell
     
         (ssh) A {Unix} {shell} program for logging
        into, and executing commands on, a remote computer.  ssh is
        intended to replace {rlogin} and {rsh}, and provide secure
        encrypted communications between two untrusted hosts over an
        insecure network.  {X11} connections and arbitrary {TCP/IP}
        {ports} can also be forwarded over the secure channel.
     
        {Home (http://www.cs.hut.fi/ssh/)}.
     
        (1997-01-07)