There are three main types of movie trailers: 1) Full-length trailers aim to entice audiences by showing scenes and music to imply the plot and genre. They last 1-2.5 minutes. 2) Teaser trailers are released about a year before the movie and provide brief glimpses or images to create hype. They are often cryptic and last 30-60 seconds. 3) TV spots are short advertisements used to target specific audiences and sell the movie through catchy songs or slogans.