This is a list of terms that Game Maker users like to throw around as if everyone understands them. If you are confused by a bit of jargon said by a Game Maker users, check this page first.
The instance actually executing the code referred to.
The room currently displayed.
controller or controller object
A special object set aside to run parts of the game not controlled by standard game objects (ie, spawning the player object again after death). The controller object is almost always never visible to the player.
object or game object
Objects in Game Maker is everything in a game that is interactive. The object representing the player is an object, the bullets it fires are objects, etc.
The object that represents the player.