Why does the bathroom mirror mists up when you have a shower?

The water vapours spread all over the bathroom when we take bath. They are on the walls, on the mirror and everywhere. However they are easily visible on the mirror as the surface is smooth and water vapours make it difficult to see clearly.

Taking showers creates a humid environment. The warm water vapor permeates the air. The mirror, and walls and everything else in the bathroom, are cooler than the air, and the moisture condenses on them. It is the same affect as water condensing on the side of your cold drink on a hot day.

same thing when you are in the kitchen