Clouds are grouped by four Latin words: "status," meaning layer; "cumulus," meaning heap; "cirrus," meaning a curl of hair; and "nimbus," meaning violent rain. The Latin words describe how the clouds look.
There are 10 main types of clouds. These are grouped by the elevation of the cloud. High clouds are the cirrus, cirrocumulus and cirrostratus clouds. These clouds are high-elevation clouds that are known for fair weather.
The mid-level or middle clouds are the altocumulus and the altostratus. These are the most commonly seen clouds and are not saturated with moisture.
The low-level clouds hang lower in the atmosphere and are the nimbostratus, the stratocumulus and stratus clouds. These have a higher level of condensation than mid-level clouds, but not the highest level.
The cumulus and the cumulonimbus are known as cross-layer clouds, because they reach upward across the lower, middle and even upper levels of the atmosphere. These are the storm clouds that can reach nine miles high and produce thunderstorms and severe weather. The cumulonimbus clouds are the most saturated with condensation. They have anvil-shaped tops from shear winds aloft. The small end of the anvil points to the wind direction.