What does the push button on a car mean?

[RowanDella]

Here is the relevant introduction about the push button on a car: push means press, and in automotive language, it has three meanings: 1. The PUSH in the middle of the air direction (also called mode) gear knob (with a glass defrosting pattern below), pressing it turns on the light and activates the rear window glass defrosting; 2. The PUSH in the middle of the temperature (also called cold/warm) gear knob (with a pattern of a half-circle with an arrow inside a car, commonly known as the internal circulation symbol), pressing it turns on the light and activates the internal circulation. 3. The third meaning of push is equivalent to the handbrake. The professional term for the handbrake is auxiliary brake, which differs in principle from the main brake. It uses a steel cable connected to the rear brake shoes to brake the car. Long-term use of the handbrake will cause the steel cable to undergo plastic deformation. Since this deformation is irreversible, long-term use will reduce its effectiveness, and the handbrake's travel will also increase. A return spring is used in conjunction with the handbrake. When the handbrake is pulled to brake, the spring is stretched; when the handbrake is released, the spring returns to its original length. Long-term use of the handbrake will also cause corresponding deformation of the spring. For small cars, the handbrake is sometimes located behind the transmission, connected to the drive shaft, where there is a brake disc, similar to a disc brake (though drum brakes also exist), and then the pulling force is transmitted there through a steel cable to achieve parking braking.