Secure Shell, commonly known as SSH, is a cryptographic network protocol used to execute commands on a remote web server or to exchange info between a server and a client. Given that the data exchanged by the two sides is encrypted, a 3rd party cannot intercept it, which makes SSH an ideal means of managing an Internet hosting account. The commands that could be executed depend on the type of hosting service. On a shared server, for instance, the choices are limited because you won't have root access to the server, so you may only create/move/delete files, set up and unpack archives, import and export databases, etcetera. They are all actions which are carried out within the shared hosting account and don't require a higher level of access. By using a virtual or a dedicated server, you'll be able to set up server-side software or to restart the server or just a certain service (web server, database server, etc.). SSH commands are submitted with a command line, but if you don't employ a UNIX-like Operating System, there are tons of apps for other OSs, which you can use to connect to the remote hosting server as well.