In regards to your question regarding the difference between a "computer" and "user":
If I am wrong.. someone please correct me

Think of a large business that has like 100 computers... and 50 employees. You would setup your server so that all of the computers can connect to the server.... and no matter which computer your employees sit at.. they also are setup to connect to the server.
The admin in this case you.. could use the server to connect to all the client computers.. and perform updates/patches etc. to all the machines from the server. You can also setup to have roaming profiles on the server... so that no matter what computer a user logs into their settings would be loaded from the server.
I have not done this ... so nobody crusify me ok..