The main classification for clouds is based on their height above ground and they are categorized as high-level, mid-level and low-level.. Clouds are also identified by their appearance and can be named by combining the root terms cirro, alto, strato, nimbus or cumulus.
Cirrus clouds, from the root cirro, for a curl of hair, are composed of ice crystals and are feathery and wispy in appearance. Cirrostratus clouds form more of a veil-like layer while cirrocumulus clouds are layered and can appear to contain areas of lumpiness. All three of these cloud types are high level and occur at an altitude of about 20,000 feet. The basis of modern cloud nomenclature was developed by Luke Howard, an amateur meteorologist and chemist, who presented his classification system to the British Askesian Society in 1802.