What is a documentary film?

A documentary film is a nonfictional movie. These films focus on facts and require detailed and in-depth research. Many directors use voiceover narration, but in recent years, other styles have become popular. Documentaries can cover a wide range of categories, including biographical topics, historical events, current events, and politics. People usually make a documentary to document an unknown or interesting angle on a topic, especially if they feel that mainstream media has not addressed a specific viewpoint.