A documentary film is a nonfictional motion picture intended to document some aspect of reality, primarily for the purposes of instruction or maintaining a historical record. Such films were originally shot on film stock—the only medium available—but now includes video and digital productions that can be either direct-to-video, made into a TV show or released for screening in cinemas. "Documentary" has been described as a "filmmaking practice, a cinematic tradition, and mode of audience reception" that is continually evolving and is without clear boundaries.