When moisture in the air cools and turns into liquid water again, it forms tiny droplets that are so light they can stay suspended in the air.
We can see these tiny droplets – we call them cloud if they're high in the sky, or fog if they're at ground level.
Some clouds are thick featureless sheets that give dull weather, while others are like bubbles and that change shape in the sky and give showery weather. The picture loop tells you more about them.
