A Tranquil Morning in Aligarh, India. Dense fog shadowed  SUN a bit though.Fog is a cloud in contact with the ground. Fog differs from other clouds only in that fog touches the surface of the Earth. The same cloud that is not fog on lower ground may be fog where it contacts higher ground such as hilltops or mountain ridges. Fog is distinct from mist only in its density. Fog is defined as cloud which reduces visibility to less than 1 km, whereas mist is that which reduces visibility to less than 2 km. Aligarh is often .foggy and in such a weather the scene is picturesque.

As a matter of fact, Smog also look like fog. Smog is a combination of various gases with water vapour and dust. Smog primarily consists of carbon monoxide, nitrogen oxides, volatile organic compounds chemically interacting with heat from sunlight forming ground level ozone. Smog is that familiar haze most commonly found surrounding large cities, particularly in the summer time. Smog and ground level ozone contribute to all kinds of respiratory problems ranging from temporary discomfort, asthma, to long-lasting, permanent lung damage. The pollutants in smog come from vehicle emissions, smokestack emissions, paints, and solvents – most of which started out as crude oil.