behind the scenes

In cinema, 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.

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