Pediatrics (or paediatrics) 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, or paediatrician. The word pediatrics and its cognates mean healer of children; they derive from two Greek words: παῖς (pais = child) and ἰατρός (iatros = doctor or healer).