A stratocumulus cloud is not as even in thickness as a stratus cloud. It has light and dark areas on the bottom, indicating, as its name suggests, that there are piles of clouds in the layer. Nimbostratus clouds sometimes may be closer to the ground. An altostratus cloud forms a smooth white or gray sheet across the sky. If the cloud is not too thick, the sun may be seen through it.
Altocumulus clouds appear in many shapes.
They might form bands or unconnected piles. A nimbostratus cloud is a smooth layer of gray. Frequently, the cloud itself cannot be seen because of the rain or snow that is falling from it. High clouds, called cirrus, cirrostratus, and cirrocumulus, are formed entirely of ice crystals. Other clouds are mainly water droplets.