Falling action is when the most exciting part in the story is turning back to neutral again. It is a series of events most likely leading up to the end of the story. They are usually at the end of the story after the problem, solution, or action.
Falling action in a story is after the climax. You can easily tell what it is in a movie, especially action movies. Anyways, falling action in a story is usually at the end and before the resolution, which is when the problem is solved. :)