Adolescence is a transitional stage of human development that occurs between childhood and adulthood. Adolescent humans go through puberty, the process of sexual maturation. Teenagers (ages 13-19) are usually adolescent, though in some individuals, puberty may extend a few years beyond the teenage years, and in some individuals, puberty begins in the pre-teen years. Usage In common usage around the world, "adolescent", "teenager", "teen", "youth", "young adult", "youngster", "young person" and "emerging adult" may be considered synonyms - although the term 'teenager' is an artifact of the English counting system, something which does not occur in all languages. The Oxford English Dictionary cites the first usage of the term to a Popular Science Monthly issue of April, 1941, "I never knew teen-agers could be so serious."In sociology, adolescence is seen as a cultural phenomenon for the working world and therefore its end points are not easily ti