Which button is for defogging?

[VanMaria]

There are two defogging buttons in a car: one is for the front windshield defogging, marked with a fan-shaped symbol containing three upward wavy lines. The other is for the rear windshield defogging, marked with a rectangular symbol containing three upward wavy lines. Below is the relevant introduction: Defogging: The principle of fog formation on the windows is caused by the temperature difference between "cold outside and warm inside." The temperature inside the car is higher than the outside temperature, leading to fog formation. Turning on the A/C switch puts it in a cooling state. The advantage of this method is quick defogging, but the downside is that it is not suitable for winter. Another method is using the heating system for defogging. This method also works well for defogging, but the drawback is that it takes a few minutes. Benefits: The car defogging button can reduce moisture, fog, and frost on the front and rear windshields and the exterior rearview mirrors, improving the driver's visibility and making driving safer.