Yes its possible to do that. I play without CD, I use steam. I can install it on every PC I want, and just need to login to Steam. You can also play offline, if you want to do single player. Multiplayer needs you to login to steam (online), but you would need the internet connection for multiplaying so thats not really a problem.
Its very recommended, it automatically updates your game and also you dont need CD or CDkey anymore.