The term documentary was used by the French to refer to any non-fiction film, including travelogues and instructional videos. The earliest "moving pictures" were by definition documentary. A broad category of cinematic expression, traditionally the only characteristic common to all documentary films is that they are meant to be factual.

They were single shots, moments captured on film, whether of a train entering a station, a boat docking, or a factory of people getting off work. Early film (pre-1900) was dominated by the novelty of showing an event.

These short films were called "actualities." Very little storytelling took place before the turn of the century, due mostly to technological limitations: cameras could hold only very small amounts of film; many of the first films are a minute or less in length.

With Robert J. Flaherty's Nanook of the North in 1922, documentary film embraced romanticism; Flaherty went on to film a number of heavily staged romantic films, usually showing how his subjects would have lived 100 years earlier and not how they lived right then (for instance, in Nanook of the North Flaherty does not allow his subjects to shoot a walrus with a nearby shotgun, but has them use a harpoon instead, putting themselves in considerable danger).