This document discusses the period of youth and adolescence. It defines adolescence as the teenage years between 13-19 when individuals undergo physical changes and personality formation. Young people are defined as those between 20-30 who are mature but still inexperienced. The document notes some typical characteristics of teenagers, such as moodiness and experimentation, and of young people, such as responsibility and maturity. It also discusses some common problems faced by teenagers and young people, such as generation gaps with parents, peer pressure, and dangers of addiction.