Pediatrics is the branch of medicine that deals with the medical care of infants, children, and adolescents. A medical practitioner who specializes in this area is known as a pediatrician.

Pediatrics differs from adult medicine in many respects. The obvious body size differences are paralleled by maturational changes. The smaller body of an infant is substantially different physiologically from that of an adult. Congenital defects, genetic variance, and developmental issues are of greater concern to paediatricians than they often are to adult physicians.