Differences between a teaser and a main theatrical trailer.

TEASER;  A teaser trailer differs from the main theatrical trailer, one way in which is that normally there will be no dialog from any actors involved. The teaser is usually supported with music from the soundtrack rather than dialog from the film. A teaser trailer is also shorter than the theatrical trailer and is also used to create suspense and 'tease' its audience rather than make the story line or plot completely clear and is also quite limited with how much information is given about the film itself and is also limited with the amount of footage from the actual film. The length of a teaser trailer is normally around one minute or less.

THEATRICAL TRAILER; The main theatrical trailer of a film is normally longer and more in depth in comparison to the teaser trailer. As the main trailer, more content of the film is used and it's used as more of an outline of the film as well as to influence its audience. The theatrical trailer is shown when the film is due to be released soon and usually lasts no longer than two minutes and thirty seconds.