Girls and boys grow rapidly during infancy and childhood, then their growth may be stable for some time until they reach puberty. Adolescence is defined as a stage between childhood and adolescence. Simply put, adolescence or puberty is a transient stage that takes a person to adolescence and is characterized by physical and mental changes in a person. After growing steadily and rapidly between childhood and adolescence, babies grow abruptly at this stage of life after which their growth may stop. Factors such as diet, exercise, genes and disease affect growth, especially physical characteristics.