Teaser Trailers vs Trailers: A Summary

So, what are the differences?

                          Teaser Trailer                                              Trailer

Timing               15 - 45 seconds                                           2 - 3 minutes

Content              Not clear, possibly confusing narrative      A more clear, straightforward narrative
                              (for both not too much content is given so that people still want to see the film)

Distribution       Around a year before film release              A couple of months before film release
                                   (both generally distributed on the internet & television adverts)