SSH, which is an abbreviation for Secure Shell, is a network protocol which is used to transfer protected information between a client and a server, making it impossible for unauthorized parties to intercept any info. Many tech-savvy clients opt for 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 can be moved or deleted, databases could be imported and exported, and archives can be created 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 could be set up and more. These things are not possible on a shared server, for the reason that full root access is needed and all the other clients on that server will be affected. Though SSH is employed largely with UNIX-like Operating Systems, there are SSH clients for other OSs too - Windows, Mac OS, and so on.