The onset of puberty is the most obvious sign of growing up physically. To put it more formally, puberty can be defined as a biological or physiological process characterized by the maturation of the sexual organs and the appearance of secondary sexual characteristics.
People often think that puberty and adolescence refer to the same thing.
However, they refer to two different aspects of growing up. While puberty covers the physical, adolescence deals with the mental and has been described as a psychosocial process characterized by mental and social growth, and often extending from puberty to the early 20s and sometimes beyond. For girls it can happen any time between the ages of 8 and 12, while for boys it usually begins a couple of years later than girls. But there is no such thing as the right time. It s as if a switch clicks on in the brain and activates a section of the brain called the hypothalamus.