Events are the missions and actions are what you do in missions. That is an example.
obj_char_create_1 Executes the command inside when the object is created in the room.
If theres action_message("Hello Y'all"); script in Create event and if you place this object to the main room (first room on the Rooms list), you will get a message box saying Hello Y'all when you start your game.
- Step: the game loop (every frame these actions are executed)
- Alarm>Alarm x: triggered when Alarm x is going off
- Draw: customize the drawing that GameMaker does