Final answer:
Adolescence is the period of transition between childhood and adulthood, marked by significant physical, cognitive, and psychosocial changes during puberty.
Step-by-step explanation:
Adolescence is the period of transition between childhood and adulthood. It starts with puberty and includes significant physical, cognitive, and psychosocial changes. Puberty is the stage of sexual maturation and growth spurt that usually begins during pre-adolescence and continues for several years into the adolescent stage. Adolescence is a time of various changes, such as the development of primary and secondary sexual characteristics, as well as the maturing of the brain, personal identity, and relationships.