SSH, or Secure Shell, is a network protocol that is used to connect to a web server and conduct different tasks using a command line. The protocol is employed by many skilled users, as the information transmitted over it is encrypted, so it cannot be intercepted on the way by a 3rd party. SSH access may be used for lots of things depending on the type of Internet hosting account. With a shared hosting account, for example, SSH is one of the ways to import/export a database or to upload a file in case the hosting server allows it. If you have a virtual or a dedicated server, SSH may be used for practically anything - you can install software or restart particular services including the web server or the database server that run on the machine. SSH is employed largely with UNIX-like Systems, but there are clients which allow you to employ the protocol if your personal computer is using a different OS as well. The connection is made on TCP port 22 by default and the remote web server always listens for incoming connections on that port although a lot of service providers change it for security reasons.