SSH, or Secure Shell, is a network protocol that is used to connect to a web server and perform various tasks via a command line. The protocol is employed by many skilled users, because the info transmitted over it is encrypted, so it can't be intercepted on the way by a third party. SSH access could be employed for lots of things depending on the type of Internet 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 it. When you have a virtual or a dedicated server, SSH could be used for practically anything - you may install software or restart specific services such as the web server or the database server which run on the machine. SSH is used largely with UNIX-like Operating Systems, but there are clients that enable you to employ the protocol if your PC is working with a different OS too. The connection is made on TCP port 22 by default and the remote server always listens for incoming connections on that port even though a number of providers change it for security reasons.