<prompt> WHO defines adolescent age between1019 years1014 years1025 years914 years  <response>: First see the difference between adolescence and puberty.AdolescenceAdolescence is defined as the period from the onset of puberty to the termination of physical growth and attainment of final adult hight, i.e. adolescence is considered as a period of transition from childhood to adulthood. Adolescence is usually the period 10 to 20 yr.PubertyPuberty is the biological process in which a child become adult, i.e. biological process which occurs during transition from childhood to adulthood. Changes include appearance of secondary sex characteristics and development of reproductive capacity. 