In diegesis the author tells the story. He is the narrator himself who presents to the audience or the readership his or his characters' thoughts and all that is in his or their imagination, their fantasies and dreams.

Diegesis in contrast to mimesis

Diegesis has been contrasted since Plato's and Aristotle's times with mimesis, the form that is showing rather than telling the thoughts or the inner processes of characters, by external action and acting. Diegesis, however, is the main narrative in fiction and drama, the telling of the story by the author, in that he speaks to the reader or the audience directly. He may speak through his characters or may be the invisible narrator or even the all-knowing narrator who speaks from above in the form of commenting on the action or the characters.

What diegesis is

Diegesis may concern elements, such as characters, events and things within the main or primary narrative. However, the author may include elements which are not intended for the primary narrative, such as stories within stories; characters and events that may be referred to elsewhere or in historical contexts and that are therefore outside the main story and are thus presented in an extradiegetic situation.

Diegesis in film

In film, diegesis is the narrative that includes all the parts of the story that are not actually shown on the screen, such as events that have led up to the present action; people who are being talked about; or events that are presumed to have happened elsewhere; in fact, all the frames, spaces and actions not focused on visually in the film's main narrative.

Film sound and music

Sound in films is termed diegetic if it is part of the narrative sphere of the film. For instance, if a character in the film is playing a piano, or turns on a CD, the resulting sound is "diegetic." If, on the other hand, music plays in the background but cannot be heard by the film's characters, it is termed non-diegetic.