what is fog?

FOG is just a cloud touching the grown.Stratus clouds appear in fuzzy layers that can hang really low in the sky.Sometimes,they sink down to the ground and become fog.All clouds from when the temperature of the air reaches the condensation point and water vapour becomes liquid .the liquid water in the air collects on dust particles and become visible as clouds.On cold or damp nights, fog can form because the air near the grown is cold and lots of moisture is in the air.As the morning warms up, the fog fades away.Fog may linger all day in valleys if the sun isn't strong.