Greetings from the Hermit WRiter.
I used the terms narrative and exposition in a recent conversation. My dialogee asked me the difference. Duh. I thought I understood it. After extensive reading, like over an hour, dude, I decided there wasn't much difference. Narrative is simply a larger pool, containing exposition, which is to explain. So, I guess narrative is the over-arcing story, while the exposition is that part that is more informative. Does that sound good?
Narrative exposition is the insertion of important background information within a story; for example, information about the setting, characters' backstories, prior plot events, historical context, etc.
In a specifically literary context, exposition appears in the form of expository writing embedded within the narrative.
Exposition is one of four rhetorical modes (also known as modes of discourse), along with description, argumentation, and narration, as elucidated by Alexander Bain and John Genung.
Each of the rhetorical modes is present in a variety of forms, and each has its own purpose and conventions. There are several ways to accomplish exposition.
Pasted from <https://en.wikipedia.org/wiki/Exposition_(narrative)>