Sven-Holger & Skuggspelet officia trailer

A trailer (also known as a preview or coming attraction) is an advertisement or a commercial for a feature film that will be exhibited in the future at a cinema, the result of creative and technical work. The term "trailer" comes from their having originally been shown at the end of a feature film screening.[1] That practice did not last long, because patrons tended to leave the theater after the films ended, but the name has stuck. Trailers are now shown before the film begins.