In filmmaking, behind-the-scenes (BTS), also known as the making-of, the set, or on the set, is a type of documentary film that features the production of a film or television program. This is often referred to as the EPK (electronic press kit) video, due to its main usage as a promotional tool, either concurrent with theatrical release or as a bonus feature for the film's DVD or Blu-ray release.
Shorter behind-the-scenes documentaries are often used as a bonus on DVDs, as it offers more insight into the film, how it was made, and to credit the film crew. Occasionally, some films have included a "making of the making-of" as a joke. The making-of is also often released for TV as a part of the promotion of the film.