Mise - en - scene

"Mise-en-scène is what we see in a film; editing is what we do not. These are simplified definitions, but they emphasize two essential things: the basic building blocks of a film—the shot and the cut—and the complexities of each that allow a film to achieve its texture and resonance. Mise-en-scène concerns the shot, though we need to keep in the back of our minds that editing—putting two shots together—affects not only how a film's narrative is structured but how the shots are subsequently understood by viewers."

Mise - en - scene is french for "placing on stage" or in media and film terms, "Everything in the frame" which is basically everything that appears before the camera in every shot.
The term was brought into film by a group of French film critics in the 1950s, many of whom would become directors and constitute the French New Wave in the 1960s.
The mise - en - scene is made by the construction of shots and the ways in which they reach the audience from shot to shot; this will include all of the elements in front of the camera which compose the shot - lighting, the placement of the characters which are in the scene, the design elements within the shot ( for example props ), comosition of the shot as a whole - how it is framed and what is in the frame. Even music can be counted as part of the mise - en - scene, even though it is not seen, music can enhance the visuals and the narrative of the shot.

Without the audience knowing, the mise - en - scene is very important in the title sequence of a film, as the audience will want to see the main charactor(s) within the first few minuets as well as the main location in which the film is set so that they are aware in what is going on, take Saw for example, in the first film within the first few seconds we knew exactly who the main characters were and the location, as well as some of the plot with out knowing too much too early; the main charactors being the victim(s), the "game master" and the location in which the "game" is set, this could be anything from a basement to an old lock up. Even though the audience will not know why the victim is in the place they are, this will be found out later on in the film when it plays out.