Secure Shell, commonly known as SSH, is a cryptographic network protocol that is used to execute commands on a remote web server or to exchange data between a website hosting server and a client. As the info exchanged by the 2 sides is protected, a 3rd party simply cannot intercept it, which makes SSH a preferred means of controlling a web hosting account. The commands that can be executed depend on the type of hosting service. On a shared hosting server, in particular, the choices are limited since you simply won't have root access to the web server, so you may simply create/move/delete files, create and unpack archives, export and import databases, etcetera. These are all actions that are executed inside the shared hosting account and don't require a higher level of access. By using a virtual or a dedicated server, you shall 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 through a command line, but if you don't employ a UNIX-like Operating System, there are tons of apps for other OSs, that you can employ to connect to the remote hosting server as well.