Below those links are several links to information about clouds. High-level clouds are composed of ice crystals and tend to be very thin and wispy. The names of clouds usually indicate both the cloud's location in the sky, as noted above, and its type, as listed below. The listings below give several examples of cloud names. Fog is a cloud on the ground.
Stratus clouds are a uniform gray and usually cover most of the sky.
Cirrus clouds are thin and high in the sky. Cumulus clouds are lumpy and can stretch high into the sky. Mammatus clouds have pouches that hang down.