SSH, or Secure Shell, is a network protocol employed to connect to a web server and carry out different tasks using a command line. The protocol is employed by many skilled users, as the info transmitted over it is encrypted, so it may not be intercepted on the way by a 3rd party. SSH access could be employed for lots of things depending on the type of hosting account. With a shared hosting account, for instance, SSH is one of the ways to import/export a database or to upload a file in case the website hosting server allows it. If you have a virtual or a dedicated server, SSH can be used for virtually anything - you can install software or restart certain services like the web server or the database server which run on the machine. SSH is used mainly with UNIX-like Platforms, but there are clients that permit you to employ the protocol if your computer is working with a different OS too. The connection is established on TCP port 22 by default and the remote server always listens for incoming connections on that port although a number of service providers change it for security reasons.