how are clouds formed????

 There are many water molecules in the air. They are called vapor. Vapor is gas and can not be seen. When air is cooled by the cold weather  each water molecules gather and tie with other water molecules. Thus vapor , water molecules they are , forms many water drops, each of which consists of many water molecules. One drop is very small and can float in the air. And when it form a large water vapour it looks like a cloud.