you may not have expertise on this kind of auto lights. Some people may mistake this kind of auto lamps for headlamps, as many of these lights are all mounted on a car's front, working to provide illumination for the driver during poor-visibility circumstances. However, fog lamps differ from headlamps both in the function and shape.
Fog lights are generally positioned below headlamps. Some car models have them mounted in their bumpers. They are usually spherical in shape. This is different from headlamps. Fog lights generally send yellow light, which has the strongest penetrating ability among all the color lights. This helps the driver to have much better visibility in foggy days or misty days. But you can find some others which produce white light, too. Sometimes white light from the bulbs may result in glare into the eyes of oncoming road users.
Currently, many aftermarket fog lights have a projector attached to the top of the inner bulb. Clear round projector is used for concentrate the light from the bulb so as to form a more focused light pattern in right front of the car.