SSH, or Secure Shell, is a network protocol which is used to connect to a server and carry out various tasks through a command line. The protocol is employed by many expert users, since the info transmitted over it is encrypted, so it may not be intercepted on the way by a third party. SSH access could be employed for a variety of things depending on the type of hosting account. With a shared hosting account, for instance, SSH is one of several ways to import/export a database or to upload a file in case the web server allows for it. If you have a virtual or a dedicated server, SSH may be used for virtually everything - you could install software or restart particular services like the web server or the database server which run on the machine. SSH is employed primarily with UNIX-like Platforms, but there are clients that permit you to use the protocol if your PC is working with a different Operating System too. The connection is established on TCP port 22 by default and the remote web server always listens for incoming connections on that port though a lot of providers change it for security reasons.