Reference

Documentary film - Wikipedia, the free encyclopedia
"Documentary film is a broad category of cinematic expression united by the intent to remain factual or non-fictional. The French used the term to refer to any non-fiction including travelogues and instructional videos. The earliest "moving pictures" were by definition documentary. 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. ..."