It has Steam. What that means is that, by purchasing this game, you're granted access to create a steam account, in which you can download tons of other games directly to your computer, as well as install games you've already purchased on however many other computers you wish. As far as I know there's no limit. The only exception being you can only have one computer logged into that account at one time, so you can't play two different games on the same account within one household, for example.
Basically Steam is everything that DRM tries to be, while not inhibiting you from enjoying your games to their fullest extent by installing bullshit SecurRom technology or anything like that. I personally love it.