SSH, which is an abbreviation for Secure Shell, is a network protocol which is used to exchange encoded info between a client and a website hosting server, which makes it impossible for unauthorized parties to intercept any info. Many tech-savvy clients choose SSH mainly because of the better security level. The connection is created and the commands are delivered using a command line. The accessible options depend on the type of hosting service - on a shared server, for example, files could be moved or deleted, databases may be imported and exported, and archives can be created or unpacked. On a virtual or a dedicated server, the choices are considerably more - the web server and the database server may be started/stopped/rebooted, server-side software could be set up and more. These things are not possible on a shared server, due to the fact that full root access is required and all the other customers on that server will be affected. While SSH is used largely with UNIX-like OSs, there are SSH clients for other OSs too - Windows, Mac OS, etc.