What is the difference between a teaser trailer and a theoretical trailer.

Teaser trailers are only used to give the audience a taste of the movie and often don't contain any actual footage from the movie itself. The time space between the teaser trailer being released and the film coming out is sometimes quite considerable as teaser trailers can come out up to one and a half years before the film. Therefore a teaser trailer, as suggested, is just to "tease" the audience giving them a sneak peak of some of the things to expect in the future. These sorts of trailers are more commonly only used with big budget films. They also don't necessarily tell the audience about the narrative of the film but to notify them that this film is being released soon so they know to look out for it. A good example of this would be The Incredibles. (2004) The teaser trailer for this movie was attached to Finding Nemo. (2003) One of the main reasons would be that both films are targeted at the same audience and made by the same animators. Astonishingly This was done a full 18 months before The Incredibles. (2004) was released. Some teaser trailers don't show the name of the movie which has been seen to be done by director J.J.Abrams on his films "Cloverfield" and the 11th "Star Trek" movie.

Above is a teaser trailer for A Nightmare On Elm Street (2010.) This is a typical trailer for a horror, or in fact any horror. Its length is quite short compared to a theoretical trailer which is much longer. The official trailer for this film is much longer and in greater depth. A feature that I really like about teaser trailer and may well include them into my own trailer is the use of fading up onto a clip and fading back down to black in rapid succession. I feel this is really effective in creating a tense atmosphere as the audience doesn't know what is going to happen next.