Narrative exposition is a literary device to introduce background information about the characters, the setting and previous events. Some procedures to display exposition are flashback, dialogues, journals or the characters' thoughts.
In "Cinderella", before the protagonist dances with the Prince, an invitation to the Prince's Ball comes to Cinderella's home. As a result, considering the course of the events, the invitation is part of the circumstances surrounding the background of the story.
