Narrator
The author and the audience both live in the real world. It is the author's function to create the universe, people, and events within the story. It is the audience's function to understand and interpret the story. The narrator only exists within the world of the story and presents it in a way the audience can grasp. In non-fiction the narrator and the author may be the same person, since the real world and the world of the story may be the same.