What does it mean to check the high-mounted stop lamp?

[JaceLynn]

Checking the high-mounted stop lamp is to warn the vehicles behind, thereby avoiding rear-end collisions. Here is the relevant information: High-mounted stop lamp: Since ordinary cars already have two brake lights installed at both ends of the rear, one on the left and one on the right. Therefore, the high-mounted stop lamp is also called the third brake light, high-mounted brake light, or third stop lamp. Function of the high-mounted stop lamp: The brake lights are installed on both sides of the rear of the car. When the driver steps on the brake pedal, the brake lights will light up and emit red light to remind the vehicles behind to pay attention and avoid rear-end collisions. When the driver releases the brake pedal, the brake lights will turn off.