What is this low, misty cloud sitting right on the ground called?

Fog forms when air near the ground cools enough that the water vapor in it turns into tiny floating droplets, exactly the same process that makes clouds high in the sky. Because fog sits right at ground level, it makes everything around you look blurry and gray.

Smoke comes from something burning, which smells sharp and often looks darker or drifts from a specific source, unlike fog's even, misty gray. Frost is frozen water that forms as a solid crust on cold surfaces like grass or windows, not a floating mist you walk through.

Some places, like San Francisco or coastal deserts, get thick fog almost daily because warm, moist air meets a cold ocean current, making fog part of the local weather pattern.