The "R" in movie ratings stands for "Restricted". It means that the movie may contain content that is not suitable for children under 17 years old, or even some adults, depending on the content. Restricted content may include strong language, intense violence, drug use, sexual content, or other adult themes. The rating is given by the Motion Picture Association of America (MPAA) and is intended to guide parents and viewers in making informed decisions about what movies they watch.