A film preview is a promotional tool used to generate interest in an upcoming movie. It typically consists of two components: a TRAILER and a TEASER. A TRAILER is a short video that gives viewers a glimpse of the plot, characters, and setting of the film. A TEASER is a shorter version of the TRAILER that focuses on creating suspense and intrigue. Both trailers and teasers are designed to get people excited about the movie and encourage them to go see it when it is released.