"Under-20" typically refers to individuals who are younger than 20 years old. This age group includes teenagers and young adults, often encompassing those from ages 13 to 19. It is a significant period in life marked by physical, emotional, and social development. In many countries, individuals under 20 are considered minors and may have restrictions on activities such as voting, drinking alcohol, or signing contracts. This age group is often the focus of educational programs and youth initiatives aimed at promoting healthy development and engagement in community activities.