Narrative is the manifestation of a story. In other words it is the mechanism via which a person gains the knowledge and understanding of that story.
Narrative comes in a variety of mediums: such as film, books, VR, AR, poetry, video games, mobile apps, theatre, dance, animation, spoken word, and many more.
Cross-media, or multi-faceted narrative uses a combination of mediums to broaden the access to the knowledge and understanding of a story. This can be particularly useful if the audience for that story is drawn from diverse social, economic and cultural backgrounds.