A film's rating generally sets the standards to help parents determine if the content is acceptable for viewing for their kids. While the MPAA doesn't release any specific guidelines to the exact type of content to receive a particular rating, it states the varying factors that affect the rating process. The more prominent factors considered in their decision refer to the film's content, primarily how much sex and nudity, adult language and topics, violence and drug use are seen and heard in the movie.
The MPAA generally defines its ratings according to the age base of the viewers. "Rated G" refers to "general audiences," meaning all types of moviegoers can watch the movie, regardless of age. "Rated PG" refers to "parental guidance suggested or advised," meaning there are some aspects or elements in the movie that may not be suitable for children and it's the parents' discretion whether to allow them to watch the movie or not. "Rated PG-13" refers to "parents strongly cautioned," meaning there are some aspects or elements in the movie that may be inappropriate to any young viewer under 13 and the children may watch the movie at the parents' discretion. "Rated R" refers to "restricted," meaning viewers under 17 must be accompanied by a parent or adult guardian when watching the movie. "Rated NC-17" refers to "no children under 17 can be admitted," which clearly means that only viewers age 17 and older can watch the movie.
Unlike a G-rated movie, a PG-rated movie can contain minimal offending theme, language, nudity, sex or violence that may not be suitable to children. Ideally, the parent or guardian must first view a PG-rated movie before making a decision of whether to allow any child to watch it or not. Because it entails both subjective and objective decisions in the part of adult decision-makers, any form of mature theme that they may deem unfit for their own children becomes the ultimate consideration for them to permit or not permit their children to watch a PG-rated movie.
The primary difference between the PG and PG-13 ratings is the gravity of profanity, violence, sensuality or sexual content in the movie. The PG rating is deemed to be more suitable for children in the general scheme of things. If the movie contains scenes with some drug use, the supposedly PG rating will automatically become PG-13. However, the themes and more mature content for a PG-13 movie is still considered to be not very realistic, extreme or persistent. Otherwise, the movie will receive an R rating.