Narrative used as a noun means: a story. The story can be real or not. Oral storytelling is the earliest method for sharing narratives.
Narrative as an adjective is used by museums, to indicate that the museum uses a 'story based' approach for their exhibitions:
"Museums are ideal places where stories can be told that encourage visitors to make their own meanings. Bedford (2001) noted that 'Stories are the most fundamental way we learn. They have a beginning, a middle, and an end.
They teach without preaching, encouraging both personal reflection and public discussion.
Stories inspire wonder and awe; they allow a listener to imagine another time and place, to find the universal in the particular, and to feel empathy for others. They preserve individual and collective memory and speak to both the adult and the child' (p.33)."