Documentary filmmaking is a very serious subject. It’s a non-fictional motion picture. Simply means a movie, which is based on facts. It can be a biopic, historical documentation, issues, culture, art, policy etc. Anything. It’s an analysis which have history, contemporary and comment on the future of the subject. Except fiction everything which comes under the sun of movie making, belongs to documentary film making. You can say It’s a pre-school of movie making.