【Haze】 ,  【mist】 ,  【fog】 ,  【smog】  denote an atmospheric condition which deprives the air near the earth of its transparency.

【Haze】 applies to such a condition as is caused by the diffusion of smoke, dust, or a light vapor through the air in such a way as to impede but not obstruct the vision and to convey little or no impression of dampness.

【Mist】  applies to a condition where water is held in suspension in fine particles in the air, floating or slowly falling in minute drops.

A  【fog】 differs from a 【mist】 only in its greater density and its greater power to cut off the vision and differs from a cloud in being near to the ground.

【Smog】 applies to a 【fog】 made heavier and darker by the smoke of an industrial area.

In extended use  【haze】 suggests vagueness or lack of clear definition of thought or feeling.

【Mist】 applies to what can be only dimly apprehended because of its remoteness or to something which prevents exact knowledge or clear understanding.

【Fog】 implies an obscuring of the mental or spiritual vision or of whatever can be detected only by such vision.