How does an engine cooling system work?

The cooling system circulates coolant (water and antifreeze mixture) through passages in the engine block to absorb combustion heat. A water pump circulates the coolant, which flows to the radiator where heat is transferred to the air. A thermostat controls coolant flow to maintain optimal operating temperature (typically 80-100C). The cooling system also includes a pressurized expansion tank, cooling fan, and heater core. Proper cooling prevents engine damage and maintains efficiency.