* Cirro-: This prefix refers to high-level clouds, which are found above 6,000 meters (20,000 feet). These clouds are typically made of ice crystals and appear thin and wispy. Examples include cirrus, cirrostratus, and cirrocumulus clouds.
* Alto-: This prefix refers to mid-level clouds, which are found between 2,000 and 6,000 meters (6,500 and 20,000 feet). These clouds can be made of both water droplets and ice crystals and have a more layered or sheet-like appearance. Examples include altostratus, altocumulus, and altofractus clouds.
So, the prefixes help us understand the approximate altitude of different types of clouds.