Screenwriting involves all writing "for the screen." Given the history of the screen, such a category covers both fiction and documentary films since the early 1900s in the United States and throughout the world as well as work for television, video, and, in recent years, the Internet. In the beginning of film, there were no screenplays. In fact, one does not need a screenplay to make a movie. Technically, one simply needs a camera and film or a digital camera, and certainly since the first days of moving images down to "Reality TV" in recent times, there are those who specialize in using nonscripted approaches to film. But the moment fiction or narrative cinema lasting more than a few minutes began to become common, there came the realization that, as for the stage, so for film, actors and directors needed to know the story, the dialogue, and the action for the tales being told.
Script credits exist for most silent films, but as biographies, autobiographies, and studies of the period have revealed, few of these films had hard and fast scripts written by someone called a screenwriter. In many of his shorts, such as The Haunted House (1921), The Boat (1921), The Playhouse (1921), The Paleface (1922), and Cops (1922), Buster Keaton (1895–1966) is listed as co-screenwriter with his friend Edward F. Cline (1892–1961). It was not until the coming of sound in film, however, that writers began to call themselves screen-writers, having to write not only action but dialogue as well.