In Warhammer: Dawn of War 2 what do multiplayer ranks do?

I don't really know why a RTS game would have ranks but other games such as COD4 or many other shooters have ranks to show how good you are at playing that game or for COD4 it unlocks guns, perks and challenges. But the only reason why Dawn Of War would have a have a ranking system would be so that others know how good you are at playing.