Pediatrics (or paediatrics) is the branch of medicine that deals with the medical care of infants, children, and adolescents, and the age limit ranges from birth up to 18 (in some places until completion of secondary education).
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: pa?? (pais = child) and ?at??? (iatros = doctor or healer).
In the United States, a pediatrician is often a primary care physician who specializes in children, whilst in the Commonwealth a paediatrician (or pediatrician) specialises in paediatrics but generally not as a primary general practitioner.