Simplify the following text for a Grade 8 native English-speaking person.
Original: The Motion Picture Association of America 's film-rating system is used in the U.S. and its territories to rate a film 's thematic and content suitability for certain audiences . The MPAA system applies only to motion pictures that are submitted for rating .
Simplified: The Motion Picture Association of America film rating system is a system used by the MPAA .