In the old days it was called the water pump, now today you may hear it referred to as the coolant pump. This is because the newer vehicles are relying on a variety of coolants and less water to do the required job. When the engine on your car is in operation its like any piece of machinery. Eventually it will get hot. In a car there are various components that are constantly operating in enclosed spaces, so there is no way of cooling it down with air. This is where the water or coolant serves its purpose.
