difference between mist and fog

mist - (манан будан, будан)Mist, however, usually stays closer to the ground and you can see over the top of it.  

A cloud that reduces visibility to less than 1 km is called fog

[uncountable, countable] a cloud of very small drops of water in the air just above the ground, that make it difficult to see
       ---- Early morning mist patches will soon clear.
       ---- The hills were shrouded in mist.
fog - (манан)fog is thicker than mist. Fog is distinct from mist only in its density(нягтрал). 

it's called mist if visibility range is between 1 and 2 km.

a thick cloud of very small drops of water in the air close to the land or ocean, that is very difficult to see through
      ---- Dense/thick fog is affecting roads in the north and visibility is poor.
      ---- Patches of fog will clear by mid-morning.

difference between mist and fog

• A: Mist is made up of tiny water droplets suspended in the air, says Brent McRoberts of Texas A&M University. "It produces a grayish-looking area over the landscape," he explains. "Fog is actually a cloud that is based at the Earth's surface and is also made up of tiny droplets and can even be composed of ice crystals if it is cold enough. The real difference between fog and mist deals with visibility. Under foggy conditions, visibility is reduced to less than one kilometer, or a little over half a mile. Mist does not reduce visibility as much as fog does."

• Both are the same.But fog is thicker than mist.If the visibility comes down below one kilometre,then fog is said to prevail.

• Although mist is not as thick as fog, they are both formed in this same way. Mist, however, usually stays closer to the ground and you can see over the top of it. Mist is often seen on autumn mornings when nights get longer and cooler again. This is particularly true in valleys, because cold air sinks down and collects in the valley during the night.

• Fog is distinct from mist only in its density. Fog is defined as cloud which reduces visibility to less than 1 km, where as mist is that which reduces visibility to less than 2 km.

• Mist and fog usually form at night when the air is too cold to hold all its moisture. Clear skies mean that the ground gets cold and it then cools the air close to it. This cool air causes condensation and water droplets form in the air. Fogs are thickest when the air can hold a lot of moisture.

• 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(үзэгдэл) of small droplets(дусал) suspended(өлгөсөн, өлгөөтэй) 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(нягтрал) 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.
  In the UK for driving purposes the definition of fog is visibility less than 200 metres, for pilots the distance is 1 kilometre.