Titles are shown at the beginning of trailers and provide information like the movie or production company name. They can also provide context about the storyline. Credits are shown at the end and list important details such as the cast, producers, and social media. Titles are used throughout trailers to inform the audience about quotes, release dates, and reviews. They identify actors, popular production companies, and the distribution company to attract viewers. Titles and credits are formatted differently based on the movie genre to set expectations and fit with the genre's conventions.