Clouds are a collection of very small drops of water or tiny pieces of ice that are held in the air. Harder - A cloud is a mass of small water droplets or tiny ice crystals that float in the air. Clouds are formed of water that has evaporated from rivers, lakes, oceans, or moist soil and plants. Most clouds continually move and change shape. Clouds change as parts evaporate in dryer air or they are moved and reshaped by wind and air currents.
Clouds are an important part of earth's weather.
Clouds carry water that falls to the earth's surface as rain and snow to then support all forms of life. Clouds can sometimes bring destruction in the form of hail or tornadoes. At this website, you learn about the different kinds of clouds, their location, where they were formed, and lots more. Here you can find explanations of and access to detailed pictures of some basic cloud forms. This site explains about clouds and how scientists measure them.