Simple teenager wearing a blue and red coloured outfit. A teenager, or teen, is a young person whose age falls within the range from 13–19. They are called teenagers because their age number ends with “teen”.
Usage by ordinary people varies, and also varies in different societies. Most societies traditionally had a formal ceremony to mark the change from childhood to adulthood. Duringpuberty, rapid mental and physical development occurs. Adolescence is the name for this transition period from childhood to adulthood.