WHAT IT'S USED FOR
In a nutshell, it is mostly used for freezing and cooling your engine, but it can also be used for HVAC (Heating, Ventilation, and Air Conditioning), which is the air conditioning unit on top of roofs of large buildings. They both, however, work in the same way...
Inside your car's engine, fuel is constantly burning. A lot of the heat from this combustion goes right out the exhaust system, but some of it soaks into the engine, heating it up. The engine runs best when its coolant is about 93 degrees Celsius. At this temperature, it is hot enough to completely vaporize the fuel, the metal parts wear less, and the oil has a lower viscosity. It also absorbs the excess heat, cooling the engine itself.
Inside your car's engine, fuel is constantly burning. A lot of the heat from this combustion goes right out the exhaust system, but some of it soaks into the engine, heating it up. The engine runs best when its coolant is about 93 degrees Celsius. At this temperature, it is hot enough to completely vaporize the fuel, the metal parts wear less, and the oil has a lower viscosity. It also absorbs the excess heat, cooling the engine itself.