Understanding the difference between a trailer and an opening sequence.

This is a trailer for the film 'se7en', The purpose of a trailer is to make the audience or viewer interested enough in the film to want to go and pay to see it. Therefore it should be exciting and keep your attention throughout, it shows the overview of what the film will include and gives a feel to the main genre of a film. In a lot of trailers, the main actors are usually shown, so that the appeal of a famous person is there. Another purpose of the trailer is so that the viewer is left curious, and by paying to watch the film, feels as if they are 'filling the gaps' left in the trailer.

The conventions of a trailer is to cram lots of information about the film, and teasers of the film into one short clip. The conventions are:
-fast paced clips of the best bits (without giving to much away)
-Fast paced editing
-Voice overs
-Energetic music
-Words related to the film appear
-website and release date