1 Auto Shop - Lights - Fog / Driving

Fog lights are intended to be used when visibility is poor and obstructed by fog, rain, or snow. They are intended to illuminate the road surface and the curb, shoulder, and edges of the road. ... In poor visibility fog lights do the job of dipped beam headlights.

In contrast, driving lights are to be used with your high-beam headlights to spot obstacles in the distance.

Driving lights produce a rectangular shaped pattern that is designed to extend beyond normal headlights. The design of the light beam will help you see much further down the road as well as on the side of the road. Driving lights are very bright and can be a distraction to oncoming traffic. You should use your driving lights when driving at high speeds on remote roads with limited visibility or on unlit highways.