It all began because of the optical phenomenon called persistence of vision. This is the means by which the eye sees separate discrete bits of information in rapid succession and interprets these as a continuous whole, a single fluid unit of sequence. In other words, the world as we see it appears as a single fluid whole, and, objectively, on the Newtonian level, it probably is, but what our physiological optic mechanism actually perceives is discrete bits of dark and light perceived in progressing (minutely) time. Another optic function called phi phenomenon fills in the blanks between discrete actions, rather like the frames of stop-action photography being run together to recreate a continuous scene. These two phenomenons are integral to seeing films--strips of individually isolated actions or scenes--as a continuous whole movie.
The first actual film strip, following experimentation with stroboscopic toys that produced the perception of continual motion out of separate pictures on spinning boards, came in 1891 and is called Fred Ott's Sneeze. Recorded at the Library of Congress, it was copyrighted in 1894. Fred Ott was gifted in the area of sneezing and William Kennedy-Laurie Dickson recorded the act as rapid motion stills on celluloid. Dickson was employed by Thomas Edison at the time and the introduction of celluloid was Dickson’s brainchild ala Fred Ott’s sneezes.
In 1895 Auguste and Louis Lumiere began filming things like female workers leaving a factory, a family at breakfast, the great outdoors, and a couple kissing. The Lumieres filmed documentaries of the real world, then in 1899 Georges Melies turned the tables with his imaginative spoof on reality called The Conjurer, which opened the doors to films like Mission Impossible and Lord of the Rings. In 1903, Edwin S. Porter took film narrative, such as The Conjurer, and production to a new level with The Great Train Robbery in which the camera defied the proscenium arch.
In theater, all action is restrained (to some extent or other) by the proscenium arch, that physical structure that separates the actors from the audience and separates the theatrical imaginary world from the audience's real world. To suspend disbelief in theater is to figuratively step behind the proscenium arch with the actors. Porter showed that to suspend disbelief in film is to follow where the camera goes. In The Great Train Robbery, Porter introduced the moving pan shot and backward and forward editing cuts to the celluloid film strips, which created a way of showing changes in time.
In Porter's pan shot in The Great Train Robbery, the robbers leave the train and, instead of walking off the visual plane of the camera lens, the camera follows the robbers away from the train and into the woods, thus defying the proscenium arch. One of the cuts--which is the stoppage of a scene and the editorial introduction of another scene--leaves the present action with the robbers and cuts back in time to the telegraph office to when and where the telegraph operator is found and revived. Thus began the humble film, which has given us Jerry Lewis pantomiming typing to jazz music; Brad Pitt as Benjamin Button, himself lost in time; Tom Hanks as a cast away; Ginger Rogers dancing backwards in heels; Nicole Kidman and Kate Hudson singing and dancing in Nine (2009); Sandra Bullock as a heroic football mom and much much more. See a film!
[Film history derived from books in Reviewer's private library.]