The major components of the Cooling System are the water pump, freeze plugs, the thermostat, the radiator, cooling fans, the heater core, the pressure cap, the overflow tank, and the hoses.
The Water Pump is part of the coolant system that protects the engine. It forces the coolant through passages in the engine to absorb heat. The pump is driven by a belt that needs replacement from time to time. And the water pump will eventually wear out and need to be replaced. Spending some money on replacing the belts and water pump is much less than the cost of repairing the massive damage that can be done when an engine seizes.