What is the difference between Teaser and Trailer?

Teasers and trailers are two different kinds of footage of a movie which allows the viewing audience to preview the upcoming film. The teaser type of footage of the movie does not give us any details about the movie. It mostly contains short clips which does not reveal as much as the trailer. A trailer provides many details about the movie. A teaser was likely photographed or filmed just before the footage of the film began.

A trailer is only completed upon the completion of the filming of the movie. Trailers generally reveal more extended previews of the movie with more dialogue and possible information about the director, producer, and the actors in the film.