Differences between teaser trailers and main theatrical trailers.

A Teaser Trailer is designed to be a smaller version of the Theatrical Trailer. It is therefore created to build up excitement about an upcoming movie, and get people excited about what is to come. A Teaser Trailer tends to be made well in advance of the film being exhibited, and rarely contains a lot of scenes from the scenes as its more likely to be made before the film has even been finished.

A Theatrical Trailer are a way to advertise the film for where it can be exhibited at the cinemas or where it will be screened and so forth. They show clips of upcoming events with in the film. The Theatrical Trailer is normally released when the film is finished, to advertise its upcoming release. It plays normally a few months or so before the film is released and normally continues to run while the film is being exhibited.