When an author decides to write fiction one the primary methods of storytelling is through a first person perspective. For many writers this is the most comfortable manner of storytelling.
In a first person narrative the reader is allowed to relate to the story one dimensionally. The story is presented to the reader from the viewpoint of a character in the story. The narrator might be the main character attempting to relate their own story. The story might also be told from the perspective of a bystander who may not be overtly involved in the storyline.
In the movie, Charlie and the Chocolate Factory, the story is narrated by a deeper male voice. It is only at the end that we discover the story was related by one of Willie Wonkas Oompa Loompas. This is an example of first person storytelling.
This type of story telling is well used in cinema. Many early filmmakers used first person narrative to present their stories. The reason this type of format was used is primarily due to early filmmaking technology that required some help in the transition between scenes. Narration provided that transition. Film noir and other detective dramas relied heavily on first...