Types of clouds can be categorized based on their altitude and formation processes. High clouds include cirrus, cirrostratus, and cirrocumulus, which form at elevations above 20,000 feet. Middle clouds like altostratus and altocumulus typically form between 6,500 to 20,000 feet, while low clouds such as stratus, stratocumulus, and nimbostratus form below 6,500 feet. Clouds with vertical development, like cumulus and cumulonimbus, can extend through multiple altitudes and are associated with severe weather phenomena such as thunderstorms and tornadoes.