Codes are rules that must be followed in filmmaking, such as establishing shots, production logos, and narrative content. Conventions do not have to be followed strictly, such as flashbacks, narration, action scenes, chase scenes, compilation of photographs, and enigma. Some examples of codes in films include establishing shots at the beginning of scenes to set the context, and production logos used by studios to brand their content. Examples of conventions include flashback scenes that interrupt the present narrative to show the past, and narration that can be used to tell the story.