ssh (SSH client) is a program for logging into a remote machine. The typical usage is ssh user@hostname, for example:

$ ssh jake@168.192.1.1

If the username is the same in the two machines (i.e., the local workstation and the remote server), the username can be omitted:

$ ssh 168.192.1.1

After you logged into the remote server via ssh, the shell runs just like you are sitting in front of the remote server. You can execute all your shell command as you normally would.

To logout once you are done:

$ exit

You will return to the shell running on your local machine, just like before you logging into the remote server.