A pediatrician is a doctor who specializes in the care of children. When a sick child goes to visit the pediatrician, often there are toys and other things to play with in the waiting room.
The word pediatrician has only been in use since the turn of the 20th century. Some people also use the word pediatrist to mean the same thing — a doctor who specializes in treating children ranging from newborn babies to adolescents. Pediatricians study pediatrics, both of which stem from a form of the Greek pais "children." The remainder of the word comes from the Greek iatros "healer."