Fly on the wall is a style of documentary-making used in film and television. The name derived from the idea that events are seen candidly, as a fly on a wall might see them. In the purest form of fly-on-the-wall documentary-making, the camera crew works as unobtrusively as possible; however, it is also common for participants to be interviewed, often by an off-camera voice. Documentary film is a broad category of visual expression that is based on the attempt, in one fashion or another, to document reality. ... Film is a term that encompasses individual motion pictures, the field of film as an art form, and the motion picture industry. ...