This document defines documentaries and outlines their key purposes and features. It discusses how documentaries aim to inform audiences about a topic using real footage or reconstructions. John Corner's theory that documentaries use recorded sound and images of actuality is also mentioned. The document then provides a brief history of documentaries, from the first being made in 1926 to their rise in popularity on television in the 1950s. Finally, it identifies different documentary types such as mixed, fully narrated, fly on the wall, and docudrama, and highlights examples of each.