Certainly in the earlier days of film, the illusion of movement was conveyed by a background that presented images that moved. For example, when the actors were in an automobile that was supposedly traveling down streets or a highway, there was a background scene that had been previously filmed which displayed other automobiles moving along as buildings passed in sight. Sometimes these images were projected behind the actors in the car seat through the automobile's rear window. If the automobile were being pursued by another, then the picture went to an automobile approaching from behind, a film that had previously been shot, as well. Another method of creating the illusion of movement has been the prior filming of the sky which has clouds moving; in fact, this method is sometimes used in contemporary films.
In modern action films, of course, computer-generated images create the illusion of movement as action figures "fly" through the air in combat, etc. Of course, with animation, action and movement are entirely computer generated. In order to convey movement, the background screen is blank and the animal or figure is moved slightly with this action repeated over and over, shooting the image twelve frames per second, reaches the designated point. The movie at the theater is run twenty-four frames per second, giving the illusion of continuous movement as special adapters improve the resolution of the film.