I doubt there's much on the disc other than information for your download to start. after it's "installed" all you have to do is log on to steam and select the game. no disc needed.
you can also "install" the game on other computers no matter where you are, but you can only open the game on one of them at a time.......... also by being logged on to steam............... blows doesn't it?............used to be a time where you purchased a game and it was yours, not a "rental".