SSH, or Secure Shell, is a network protocol employed to connect to a server and carry out different tasks using a command line. The protocol is preferred by many expert users, because the info transmitted over it is encrypted, so it cannot be intercepted on the way by a 3rd party. SSH access may be employed for a lot of things with regards to the type of 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 if the hosting server allows it. If you have a virtual or a dedicated server, SSH can be used for pretty much anything - you can install software or restart particular services like the web server or the database server that run on the machine. SSH is used mostly with UNIX-like Operating Systems, but there are clients which enable you to use the protocol if your PC is running a different Operating System too. The connection is created on TCP port 22 by default and the remote web server always listens for incoming connections on that port although lots of providers change it for security reasons.