A trailer is tailor made to do a few things: 1. Get the audience excited for the film the studio is marketing. It should give you an idea what the story is about, but give little away as possible, something many trailers seem to forget these days. 2. Get a buzz going about its release. The more people talking about it, via word of mouth or by social media, the better. 3. Get the fanboys and/or fangirls (the built-in audience who read up on movie sites every nugget of information on the movie or film series that they can find) excited about what is coming their way in months or in a year's time. That's the job of a trailer. A teaser, on the other hand, works the same way, but with one big difference: A teaser is like foreplay (for lack of a better word); it's designed to get you excited and whet the appetite for the audience. A teaser is basically something the filmmakers want to show off. The effects aren't completely done yet, the final product is still in the