There are Pediatricians who practice primary care, taking care of the general needs of children, and there are others who specialize, for example, only treating kids with cancer, heart problems, kidney problems, etc.
Pediatricians take care of children. This might involve treating an ear infection, talking to parents about school or behavioral problems, or seeing them for well child checkups and giving them their shots.
Pediatricians diagnose and treat infections, injuries, and many types of organic disease and dysfunction. They work to reduce infant and child mortality, foster healthy lifestyles, and ease the day-to-day difficulties of those with chronic conditions.