Girls and boys grow at a quick pace through infancy and childhood, after which their growth may see to stabilize for some time until they hit puberty. Puberty is defined as the phase that lies right in the middle of childhood and adulthood. To put it simply, puberty or adolescence is the transitory phase that takes one to adulthood, and is characterized by physical and mental changes in an individual. After growing at a steady and quick pace through childhood and infancy, children exhibit a sudden spurt in growth during this phase of life after which their growth may stop. Factors such as diet, exercise, genes and disease affect growth, especially physical characteristics.