Understanding the difference between a trailer and an opening sequence

The purpose of a trailer is to encourage the audience to watch your film and make them go out and watch it or buy it .Whereas a title sequence is what builds up tension leading into the main parts of the films. It also shows us the job roles and who done them.

Trailers Include:

A voice over
Clips from film
Cliffhangers
Most exciting parts
Quick shots

Opening sequence includes:

Soundtrack
Actors
Job roles and who done them
It has to be interesting

Se7en Trailer:

As You can see, they show good points within the film and short sharp shots. This automatically gives the audience a feeling of wanting to watch the film.

Se7en Opening Sequence:

The opening sequence starts off with the credits and saying who was the producer and other roles that were fulfilled within the film. it also gives us a soundtrack that starts the film off in a very mysterious way.