SSH, which is an abbreviation for Secure Shell, is a network protocol employed to transfer encrypted information between a client and a web server, which makes it impossible for unauthorized parties to intercept any info. Many tech-savvy clients choose SSH because of the improved level of security. The connection is made and the commands are sent via a command line. The available options depend on the type of web hosting service - on a shared server, for example, files could be transferred or deleted, databases can be imported and exported, and archives may be set up or unpacked. On a virtual or a dedicated server, the choices are a lot more - the web server and the database server may be started/stopped/rebooted, server-side software can be installed and much more. These things aren't possible on a shared server, since full root access is needed and all the other clients on that server shall be affected. Even though SSH is used primarily with UNIX-like OSs, there are SSH clients for other OSs too - Windows, Mac OS, and so forth.