<human>:  Could you explain the different types of clouds to me in layman's terms and how they form?
<bot>: Clouds are huge collections of tiny water droplets or ice crystals floating in the sky. They form when air rises and cools to its dew point, which is the temperature at which air can no longer hold the water vapor it contains and the water vapor condenses into liquid or ice. There are several main types of clouds, categorized by their height in the sky and their shape. Low-level clouds include Stratus clouds, which are gray, flat layers, and Cumulus clouds, which have puffy tops and appear like floating pieces of cotton. Mid-level clouds are composed of Altocumulus clouds, which appear as small, puffy round mounds, and Altostratus clouds, which are layered and sometimes produce light rain or snow. High-level clouds are Cirrus clouds, which are thin and wispy, and Cirrostratus clouds, which are thin and spread out in a layer.