Your cooling system is what keeps your car from having a meltdown. If you didn't have some way to cool things off, your engine would turn into a solid block of useless metal in no time flat.
All of the parts that make up the cooling system have one goal of moving coolant around the engine so it can absorb and dissipate heat.
Radiator The radiator is the most prominent part of the system.
Coolant that has traveled through the engine is pumped through the tubes of the
radiator and is cooled off for another round.
Radiator Hoses Your cooling system has a number of rubber hoses that
move the fluid from one place to the other. These need to be replaced before
they become brittle and cracked.
Water Pump The water pump does what you think it does - pumps the
coolant through the system. The pump is belt driven, except in the case of some
race cars that use an electric water pump.
Thermostat Your engine isn't always the same temperature. When you
start it on a cold morning, you want it to get warm quickly. If you stop in
traffic, you want it to cool itself off. The thermostat controls the flow of
coolant so that it cools down more or less depending on the temperature of the
coolant.
Electric Cooling Fan Many cars these days have an electric fan for
either primary or added cooling. The fan draws air through the radiator when you
aren't moving fast enough to get things cooled down.
Thermo Time Switch Also known as the fan switch, this is the
temperature sensor that tells the electric fan when to blow.