A movie preview is a short advertisement for an upcoming film. It typically consists of three components: a CLIP, a TEASER, and a TRAILER. A CLIP is a short excerpt from the film, usually no longer than a few minutes. A TEASER is a brief advertisement that does not show any footage from the film, but instead hints at the plot or characters. A TRAILER is a longer advertisement that includes clips from the film and often reveals more of the plot.