SSH, which is an abbreviation for Secure Shell, is a network protocol that's used to exchange encoded info between a client and a server, which makes it impossible for unauthorized parties to intercept any data. Many tech-savvy users opt for SSH mainly because of the better security level. The connection is established and the commands are sent via a command line. The available options depend on the type of Internet hosting service - on a shared server, for example, files may be moved or deleted, databases may be imported and exported, and archives may be created or unpacked. On a virtual or a dedicated server, your choices are significantly more - the web server and the database server may be started/stopped/rebooted, server-side software could be set up and a lot more. These things aren't possible on a shared server, because full root access is needed and all the other clients on that server shall be affected. Although SSH is employed mainly with UNIX-like OSs, there are SSH clients for other OSs as well - Windows, Mac OS, and so forth.