A documentary is a film, television, or radio program that provides a factual report on a particular subject using pictures, interviews, or official documents. Some key conventions of documentaries include: 1) Using voiceovers to allow the filmmaker to narrate over footage and speak to viewers. 2) Conducting interviews to ask specific questions about related subjects. 3) Incorporating archival footage to make events seem more real. 4) Adding titles, labels, and dates to anchor images and convey information efficiently. 5) Reconstructing past events or typical scenes to quickly illustrate concepts.