There are three main types of film posters: teaser posters, main posters, and character posters. Teaser posters contain basic information like the stars and release date to intrigue audiences without revealing much about the plot. Main posters provide more details about the production, stars, and distributors. Character posters focus on highlighting one or more of the main actors, especially if they are a major selling point. Consistency across different marketing materials like posters and trailers is important for building familiarity and recognition with audiences.