Fog and Haze are similar but the main difference between haze and fog is that fog is caused by tiny water droplets while haze is caused by air pollutants such as dust and other tiny debris that can occur in the air.
Haze usually happens when there are strong wind gusts that pick up dust and dirt and throw them through the air but haze can also occur when the pollutants in the air came from miles away even with no wind.
The fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface.
Haze is the atmospheric phenomenon in which dust, smoke, and other dry particulates obscure the clarity of the sky.
Both haze and fog can reduce your visibility and so you must drive carefully through the haze or fog if need be.
Fog is not harmful to your health to breathe at all because it's just moisture and water droplets in the air but haze can sometimes be harmful to your health because it can contain other pollutants.
When you have to be outside in the haze it's a good idea to wear a face mask to prevent health issues from breathing in the pollutants from the haze.