Is it possible to use servers to mine bitcoins? I have a vps, it's debian but i can install any os, i don't use it a lot, can i use it to mine bitcoins? Correct me if I'm wrong, bitcoins uses video cards, and as far as i know, vps and dedicated servers don't have video cards.

So therefore I'm asking, is it possible to use servers to mine bitcoins
It is possible, but not profitable.  Even if you consider the server as already paid for you will not generate nearly enough of a hashrate to earn more than a few cents a month.