The three main types of clouds are Cumulus, Stratus, and Cirrus.
Cumulus Clouds:
These are the fluffy puffy clouds; many people say that these clouds look like cotton! Cartoon clouds typically resemble Cumulus clouds with the flat bottom and the puffy top. They are found below 6,500 ft.
Cirrus Clouds:
Nearly the opposite of Cumulus clouds, these are the wispy, thin, and "feathery," clouds. Generally, they accompany sunny weather and are found at heights of 20,000 ft. or higher.
Stratus:
These are the what people usually call storm clouds. Typically, these will bring some form of precipitation, whether it be rain, or snow! A lot of the time, they look like gray blanket covering the sky, since they are flat and spread across the sky. Like Cumulus clouds, they are located at heights of 6,500 or lower.