What does 'dual' mean in a car?

[OJasmine]

The 'dual' button in a car refers to the dual-zone climate control feature. When this button is pressed and its indicator light illuminates, it allows separate temperature settings for the driver and front passenger areas. After adjusting to the desired temperatures, turning off this button will make the automatic air conditioning system maintain the preset temperature values. The purpose of dual-zone climate control is to enable the AC system to effectively track load variations, improve cabin thermal comfort, and reduce energy consumption. A car's air conditioning system consists of a compressor, condenser, expansion valve, evaporator, blower, and necessary control components, working together to regulate cabin temperature and humidity for occupant comfort.