Fog: Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface.

Haze: Haze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky.

Smog: is a type of air pollution; the word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog.