
Owen D. answered 01/11/20
Experienced Urban Educator Specializing in Reading and Writing
The exposition of a story is the set up. In the exposition, usually, the setting is revealed, as well as the major characters. You know that the exposition is over when conflict is established (you know what problem the characters have).
If the setting changes, or we get another major character in the story, there is usually a little exposition involved. For example in A Wrinkle in Time when they tesser to another planet we get a description of the planet and its creature before we find out how the characters being their adds to the conflict.