Teenagers Teen Age describes a period of child-growth that extends from the thirteenth to the nineteenth year. It corresponds generally to the period of development known as adolescence, which may begin before the age of 13 and extend well beyond the age of 19.
Adolescence actually begins with puberty, a period during which the child matures physically.
Adolescence ends at some indefinite point called maturity, or adulthood. Adults have certain special characteristics that adolescents usually lack. But the chief factor of adulthood is physical maturity, which is generally completed between the ages of 20 and 23. Physical changes sometimes upset him emotionally. The teen ager also strives for the independence, freedom, and responsibility of an adult.