SSH, or Secure Shell, is a network protocol which is used to connect to a server and carry out different tasks using a command line. The protocol is preferred by many experienced users, as the data transmitted over it is encrypted, so it cannot be intercepted on the way by a 3rd party. SSH access can be employed for lots of things depending on the type of Internet hosting account. With a shared hosting account, in particular, SSH is one of the ways to import/export a database or to upload a file if the hosting server permits it. When you have a virtual or a dedicated server, SSH could be used for pretty much anything - you may install software or restart particular services such as the web server or the database server which run on the machine. SSH is employed typically with UNIX-like Operating Systems, but there are clients which allow you to use the protocol if your computer system is using a different Operating System as well. The connection is established on TCP port 22 by default and the remote hosting server always listens for incoming connections on that port although a number of service providers change it for security reasons.