Hosting multiple servers on 1 pc?

So I looked online and couldn't really understand and really get the solid source answer for this concept.

Providing my VPS and withstand the processing power required for 2 servers, how can I go about hosting 2 servers at once?

/hosted different workshops
/different addons enabled (or does my addons have to be cross-compatible with darkrp & ttt)

Any info would be great. I'd be nice to be able to have more than just 1 server running and not have to buy a new vps or whatever else cases may be.