Fog is a cloud bank that is in contact with the ground. Fog is
usually the only clouds that touch the ground and it only differs
slightly from other clouds in that it touches the surface of the Earth.
The same cloud that is not fog on lower ground may be fog where it
contacts higher ground such as hilltops or mountain ridges.
Mist is a phenomenon of small droplets suspended in air.
It can occur as part of natural weather or volcanic activity, and is
common in cold air above warmer water, in exhaled air in the cold, and
in a steam room of a sauna. It can also be created artificially with aerosol canisters if the humidity conditions are right.
The only difference between mist and fog is density and
its effect on visibility. A cloud that reduces visibility to less than 1
km (about 1,094 yards or 0.62 miles) is called fog, whereas it �s called
mist if visibility range is between 1 and 2 km.