I love Starcraft. When Broodwar came out I really dug the additional units they added and tore through all the campaigns. When Starcraft 2 was announced I was ecstatic. All I really wanted was Starcraft with an upgraded interface and smooth graphics, the original formula I felt was perfect. I pre-ordered the collectors edition(as I sort of do now days) and when the game launched I raced through the single-player game.
The game is fantastic. It takes place after Broodwar and stars Jim Raynor as the leader of the human opposition to General Mengsk and the other...

So how do all these games fit together? I know the first Starcraft 2 was Terran only, and Heart of the Swarm is Zerg. Are they separate games, or is Heart of the Swarm an expansion? Based on some pre-orders I've seen, they are both a full $60.
Starcraft 2 was Terran only for single player WITH some added Protoss levels. Multiplayer allowed you to play as Terran, Zerg and Protoss fully. Heart of the Swarm is the Zerg single player with additional units to multi-player. As far as the price, I am not sure I wouldn't be surprised if it was $60.
Oh yeah I know multiplayer allowed you to do all three. I'm just curious if they'll all fit together as one game or if they're three separate games.
The sort continues from game to game. For instance the thing to do at the end starts up Heart of the Swarm.