Movie trailers are short videos used to promote upcoming films. Teasers, which are seven letters long, are typically the first type of trailer released and are designed to create interest in the film. PREVIEWS, which are eight letters long, are usually released closer to the film's release date and provide more information about the plot and characters. Sequels, which are also seven letters long, are trailers for films that are part of a series and are used to remind viewers of the previous films in the series.