Age appropriateness

Age appropriateness or child-friendly is the progression of behavioral norms largely agreed upon within a society or among sociological and psychological authorities to be appropriate to a child's development of social skills. These behaviors are divided into a number of development stages based upon the child's age.
Lack of exposure to age appropriate activities and experiences is commonly thought to prevent a child from gaining the skills necessary for their current and thus their next stage of development.
Toys.
In the United States, age determination guidelines for toys and games are suggested by the U.S. Consumer Product Safety Commission (CPSC) and consider child development (for children under 12 years of age) and toy characteristics. When considering child development, the CPSC looks at the physical development, cognitive development, emotional development and social development of children. The CPSC guidelines are then separated into four categories which include: play categories, toy subcategories, age groups, and toy characteristics. Another notable factor relating to the age appropriateness of toys is whether or not the toys contain small parts, which can pose a potentially fatal choking hazard to young children, as younger children are more likely to put the small parts in their mouths.
Media and film.
Content ratings often indicate at which age that content is considered by the rating body to be age-appropriate. For example, in the United States, TV-14 indicates that the television program contains some material that many parents would find unsuitable for children under 14 years old; it is the equivalent to PG-13 for motion pictures.
While ratings often classify material as inappropriate for children, the term "adult film" most often refers to pornography.
The Canadian Home Video Rating System is voluntary in most provinces of Canada, and the CHV rating system is as follows:
Similar systems based on age appropriateness include the Korea Media Rating Board, the Movie and Television Review and Classification Board of the Philippines, the Office of Film and Literature Classification (New Zealand), the British Board of Film Classification, the Australian Classification Board, and the Film Classification and Rating Organization (Eirin) of Japan.