Secure Shell, better known as SSH, is a cryptographic network protocol used to execute commands on a remote hosting server or to exchange information between a website hosting server and a client. Since the info exchanged by the 2 sides is encrypted, a 3rd party simply cannot intercept it, which makes SSH a favorite means of managing a web hosting account. The commands that could be executed are determined by the type of hosting service. On a shared hosting server, in particular, the possibilities are limited because you will not have root access to the server, so you may only create/move/delete files, set up and unpack archives, export and import databases, etc. They're all actions that are executed within the shared hosting account and do not require a higher level of access. Through a virtual or a dedicated server, you will have the ability to install server-side software or to restart the machine or only a specific service (web server, database server, etc.). SSH commands are submitted through a command line, but if you do not use a UNIX-like Operating System, there are plenty of applications for other OSs, which you can employ to connect to the remote hosting server as well.