Answer:
Assuming you're asking what it is so an exposition is "a comprehensive description and explanation of an idea or theory.
Explanation:
So in other words, it's a description and/or explanation of what a story might be about. Another definition is "Exposition is a literary device used to introduce background information about events, settings, characters, or other elements of a work to the audience or reader." Exposition is crucial to any story, for without it nothing makes sense. Click on the link below if you need more help.
Link: https://literarydevices.net/exposition/
Hope this helps.