Comebackids

Just about to start out and I was wondering how servers work in this game? Is it like runescape where I can switch servers at will and keep all my progress/character or is it like other mmo's where characters are tied to that particular server? Asking because a friend of mine is on red and the que times are ridiculous, but if I can play on Yellow then log onto Red some other time to battle/trade some other time then I'd prefer to do that.