Air conditioning was an invention that made the South a viable place to live and do business. When they figured out how to add it to your car, the trip there and back got a lot better, too. Your A/C system may seem complicated, and it is, but it's also easy to understand, and has some parts that you can service yourself.
How it Works, Basically
Any system that lowers temperature operates in similar fashion. First you take a gas, like Freon, and place it in a sealed system. This freon is then pressurized using a compressor. As it's pressurized, it gets hot by absorbing the heat around it. This hot gas is then circulated through a series of tubes that dissipate the heat. Scientifically, the gas removes heat rather than adds cold, but that's a lesson in physics that doesn't really matter to us right now. The gas can lose lots of its heat, in other words it gets really cold, when you reduce the pressure. As it cools it becomes a liquid. This is when you get cold air blowing on your sweaty forehead.
To use this system in a car, it needed very little adaptation from its early applications as a refrigeration device. since it was discovered that Freon (R-12) was harmful to the earth's Ozone layer, it's been phased out for automotive use, and replaced with the slightly less efficient, but harmless R-134a refrigerant. This is actually good news because for years it was against the law to service your own air conditioning system without a license. Now that the refrigerant is safer, we can all work on our own A/C systems again! Some cars have not been converted from the old R12 to R-134a, but this conversion can be done easily.