The transition from childhood to adulthood is a universal process that varies greatly by individual and by region, country and culture. The beginning point of this transition for both females and males is usually considered the onset of puberty, which occurs at various ages. There is no clearly defined ending point for the transition from childhood to adulthood. Puberty is the physical process of sexual maturation that includes the development of secondary sexual characteristics, such as breasts for girls and increased pubic hair for boys and girls.
Puberty occurs gradually over several years.
In addition to becoming physiologically mature during this transitional stage, youth undergo psychological and cognitive changes. Young people become less dependent on parents and more involved with peers. They begin to form identities as individuals and develop further capacity for interpersonal relationships. During this time, young people often move from being socially and financially dependent to being relatively independent. In certain cultures, other events or processes also help to define this transition, such as formal initiation practices and traditions.