What is the difference between fog and haze?

Fog and haze are both atmospheric phenomena that reduce visibility, but they differ in their composition and density. Fog consists of tiny water droplets suspended in the air, creating a thick, low-lying cloud that significantly reduces visibility to less than 1 kilometer. In contrast, haze is caused by the presence of fine particles, such as dust or pollution, in the air, which can scatter light and reduce visibility but typically does not form a dense layer like fog. While fog often leads to a more substantial drop in visibility, haze generally results in a more gradual decrease.