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 website hosting server and a client. Given that the information exchanged by the two sides is encrypted, a third party cannot intercept it, which makes SSH an ideal means of controlling an Internet hosting account. The commands that may be executed are determined by the type of hosting service. On a shared web server, for instance, the alternatives are limited as you will not have root access to the web server, so you can just create/move/delete files, create and unpack archives, export and import databases, etc. They are all actions which are executed within the shared hosting account and don't require a higher level of access. By using a virtual or a dedicated server, you shall have the ability to set up server-side software or to restart the web server or only a specific service (web server, database server, etc.). SSH commands are submitted through a command line, and if you don't employ a UNIX-like Operating System, there are plenty of apps for other OSs, that you can employ to connect to the remote web server as well.