Adolescence varies person to person. Generally it begins from 11yrs for some girls or even boys and some people at 13. It is phase when a boy or a gets their reproductive organs and and reaches their mental maturity. It is a period between infancy and adulthood & Teenage means 13 to 19 years of age, So that is the reason why adolescence is also called teenage.

Adolescence vs Teenage

Adolescence
Adolescence is a period of significant physical, emotional, and psychological development that occurs between childhood and adulthood. It typically begins around the age of 10-12 and ends in the late teens or early 20s. This stage is characterized by rapid growth, hormonal changes, and the development of identity and independence.

Teenage
Teenage is a term often used interchangeably with adolescence to refer to the period between childhood and adulthood. It specifically refers to individuals who are in their teen years, typically between the ages of 13 and 19. During this time, teenagers experience a range of physical, emotional, and social changes as they transition from childhood to adulthood.

Why adolescence is also called teenage
- Similar age range: Adolescence and teenage years typically overlap in terms of age range, with both referring to individuals in their early to late teens.
- Common characteristics: Both adolescence and teenage years are marked by similar developmental milestones, such as puberty, increased independence, and forming personal identities.
- Cultural connotations: The term "teenage" has become synonymous with the challenges and experiences of adolescence in popular culture and media.
- Social norms: In many societies, the teenage years are seen as a distinct stage of life characterized by unique behaviors and attitudes, further contributing to the association between adolescence and being a teenager.

In conclusion, adolescence is often referred to as teenage due to the overlapping age range, shared characteristics, cultural connotations, and social norms associated with both stages of development.