The Steam system has always confused me, so I need someone to clear this up for me. 
 
Can you list the different "kinds" of games that Steam provides? What I mean is, some of them are independent from Steam and have the same save location of the non-Steam version, whereas others have Steam cloud saves that you can't back up, etc.. 
 
What I'm trying to ask here is, how do I know whether a game, even if I buy the hard copy of it, will require Steam to be played (like MW2) or not? Is that what Steamworks is? That a game is only available to launch through Steam? 
 
Steamworks, Steamplay, Steam cloud, what's all that stuff about?

Steamcloud is just a save thing, it's saved on a server owned by Steam. Steamworks means that the game will work through Steam. I have no idea what Steamplay is. I think it's a Mac thing.

Steamplay basically means you own both the mac version and pc version. All mac games have Steam Play.

@AhmadMetallic said:

whereas others have Steam cloud saves that you can't back up,

Steam Cloud saves are by definition backed up.

@AhmadMetallic said:

@rebgav: How do I know whether a game has Steamworks or not? I'm checking out the Just Cause 2 page and it doesn't say it anywhere. It only says Steam Achievements and Cloud. I really hate Steamworks and having to run a game through Steam to play, it's just inconvenient.

I love steam keeps all my games in one spot. I here people bitching all the time about having to run steam like its some massive cpu hungry beast that runs in the backround bogging your shit down while you play. NOT TRUE! Also the deals are great! Sales all the time midwwek madness and so on. I would never say steam is inconvenient. Orign is not even as bad as people say it is but most of the people that bash on origin are steam/valve fans. Running GFWL on a steam game ya that does suck and is very stupid.

@AhmadMetallic said:

@rebgav: How do I know whether a game has Steamworks or not? I'm checking out the Just Cause 2 page and it doesn't say it anywhere. It only says Steam Achievements and Cloud. I really hate Steamworks and having to run a game through Steam to play, it's just inconvenient.

Are you a time-traveler from 2003 or something? Here in the future, Steam has a low CPU footprint and things like Friend Lists, automatic updating, driver updates, badass sales, and free TF2.

However, if you still want to be an anachronist, you can just right-click on JC2 and create a desktop shortcut that will bring you straight into the game.