Concave mirror can gather light and use it on car headlights to make the light parallel and illuminate the road ahead. Convex mirror can disperse light, and it can be used in automobile rearview mirror. Convex mirror can become a vertical and narrow virtual image, which can increase the driver's observation range and reduce traffic accidents.
Headlights are internal convergent light sources, and mirrors must be concave lenses. The principle is to concentrate all the light refracted by concave lens at one point.
Just like a TV antenna pot, the weak signal wave is concentrated at one point to enhance the signal source. Our headlights also concentrate the light source in this way, and then shine on the concave-convex glass surface of the headlights and illuminate according to our design requirements.