What does the AC button in the car mean?

[IvanFitz]

The AC button in the car is the cooling switch of the car air conditioning. When the weather is hot and you need to turn on the air conditioning to cool down, you can press this button, and then the indicator light will turn on, starting the work of the car air conditioning compressor, blowing cold air from the vents to lower the temperature inside the car. When using the air conditioning for heating in winter, the AC light being on does not help with heating at all, so it can be completely turned off when using the air conditioning for heating in northern winters. Another common button on the air conditioning is SYNC, which is the synchronization button for the dual-zone automatic air conditioning. Pressing SYNC once makes the temperature of the vents on both sides of the car the same and synchronizes the adjustment. When turning on the air conditioning, if you set different temperatures on both sides, SYNC will automatically turn off.