The water pump is a centrifugal pump driven by a belt connected to the crankshaft of the engine. It circulates coolant form the radiator, through the engine, and back to the radiator. The water pump has a shaft with a pulley on one end and a pump rotor on the other end. When the pulley is spun by a belt, the rotor starts to circulate the coolant.
Car water pumps have an inlet near the center so the coolant returning from the radiator hits the pump vanes. The pump vanes fling the coolant to the outside of the water pump, where it enters the engine.
Auto water pumps have various designs for different purposes. Most include a rotating impeller, which transmits the coolant through the engine block. As for most rear-wheel drive cars, the fan is installed on the end of the water pump shaft. These car water pumps usually have a spring-loaded seal to prevent water leakage around the pump shaft. Some water pumps are fitted with pre-packed ball bearings sealed at each end so lubrication won't be necessary. It is a must to have a fully-functioning water pump to avoid overheating and engine wear and tear engine. The circulating capability of an auto water pump will certainly cool your engine down at a manageable temperature.