Haze is primarily a visual description. It is something in the air that interferes with clear vision of objects in the sky, or off in the distance. You can have haze even without pollution. Even clean air scatters blue light, and obscures distant objects, like mountains, with a bluish haze. Fog and mist are similar, but fog is thicker. Fog is basically a cloud that is at ground level instead of in the sky. Fog feels distinctly moist on the skin. I have been in fog that was so thick that I literally could not see my hand at arms' length. Fortunately, it was just a small pocket that had collected in a depression in the ground, perhaps a fifty meters across. Warning, here comes a pun (play on words). A group of travelers climbed a trail. The trail led to a viewpoint with a spectacular, panoramic view. Unfortunately, there was fog moving in. When they got there, they couldn't see a thing. Their guide said, "Well, we've missed the view, but we may view the mist."

They are not the same. Here are my personal definitions. Haze - Pollution or smoke in the air. The air is "gray" instead of being clear. Visibility seems normal but far away hills may not be visible. Mist - Tiny water droplets in the air. The air is "gray" instead of being clear. Visibility is limited. Fog - Tiny water droplets in the air. The air is "white." Visibility is extremely limited (from 5 m in heavy fog to 100 m in medium fog). Here are the dictionary definitions. New Oxford American Dictionary haze | heɪz | noun 1 a slight obscuration of the lower atmosphere, typically caused by fine suspended particles. • a tenuous cloud of something such as vapor or smoke in the air: a faint haze of steam. mist | mɪst | noun a cloud of tiny water droplets suspended in the atmosphere at or near the earth's surface limiting visibility, but to a lesser extent than fog; strictly, with visibility remaining above 1.5 miles (1 km): the peaks were shrouded in mist | [in singular] : a mist rose out of the river. fog | fɔɡ, fɑɡ | noun 1 a thick cloud of tiny water droplets suspended in the atmosphere at or near the earth's surface which obscures or restricts visibility (to a greater extent than mist; strictly, reducing visibility to below 1 km): the collision occurred in thick fog.

Well, this is my assessment, others may disagree. Mist would be like a super fine light rain. Fog is basically like clouds on land. Naturally they vary in "thickness" Haze is associated with pollution, dirty skies etc.

Yes, but most people use interchangeably however: Mist and fog are both caused by water droplets in the air. Fog is when visibility is less than 1km, and mist is when it's in the distance. Haze is the sunlight off air pollution. https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/fog/difference-mist-and-fog

Heat-haze is a visual effect. Experienced on hot days. "Haze" is also used in some places to mean a general effect, including smog. "Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates obscure the clarity of the sky." The idea is that it's a visual effect, or the thing that causes the effect, when looking up wards, or across at the sky. Mist is light, thin, like thin cloud. Mist is what you see from the mountain top down and lies in valleys on cold mornings. If you go down it has the sense of water as being in the clouds. It shifts around you obscuring some things, then others, this hill, then that building, but only in areas, not so thick as to block your view completely. Mist is white. https://en.wikipedia.org/wiki/Mist When you go up a mountain into the cloud, it has the same effect and would be called mist. Fog is dense, difficult to see through. Makes it difficult to see your feet. Other things are obscured. https://en.wikipedia.org/wiki/Fog Both mist ang fog are water-based, white. It becomes smog if you add smoke. Smog is white to brown, smells like smoke, not always good to breathe.