actually you just receive a VAC ban, so you will not be able to play online on any server using VAC, you can still play your steam games, buy games, trade, ect...
getting a steam ban would require more serious actions such as using stolen credit cards to purchase games, directly editing steam client files (such as trying to add steam games to your account you did not purchase), phishing, and using hacked clients
VAC bans are game based.
If you get banned in MW3, you can still play (online) other games, including the other CoD games. You only get banned in that particular game.
Getting a ban in a goldsrc game means you'll get banned from all the games using goldsrc since the ban is engine based. This was the same with Source games (TF2, CSS, CSGO, etc) but they changed it sometime ago.
And the ban only covers the multiplayer portion of the game. You can still run the game and in the case of TF2, connect to a non-secured VAC server.
And to clarifiy, to get banned in any of these games or engines, you need to be running a injector/program that modifies core game files while you're playing in a VAC secured server.
So, if you're running a cheat for TF2 while you play, let's say, Saints Row 4, you won't get banned from SR4 (that game isnt VAC bannable) or TF2. You can also be running the cheat while on TF2 menu. You won't get banned. You need to establish a connection with a VAC secured server for VAC to be running.
So running pirated copies of games and software and adding them to your library won't get you banned.