There are generally five basic parts to a story: the exposition, the rising action, the climax, the falling action, and the resolution (sometimes called the 'denouement').

The exposition introduces the story in general and usually contains an 'initial incident,' which is an action that begins the conflict and draws the reader into the story.

The rising action is the series of events leading up to the climax. There may be plot twists, new characters introduced, or other events the protagonist must handle. 

The climax occurs when there is the greatest tension in the story and the events reach a crisis point.

Then comes the falling action. Falling action is the series of events just after the climax, sort of a 'slowing down' of the action as the story draws to a final close, which is the resolution.

In Oedipus Rex, the falling action occurs right after the climax in which Oedipus finds out he is the man who has brought the plague on Thebes when he unknowingly killed his father and married his mother. 

In the falling action, a messenger delivers the news that Jocasta is dead, then another messenger announces that King Oedipus has blinded himself. The ruined king asks Creon to banish him from Thebes for the rest of his life, and he visits his children one last time before he leaves.