Clouds are made of very tiny drops of liquid water called cloud drops or cloud droplets.
Cloud droplets stick together to form larger heavier raindrops, which fall to the ground where they collect in puddles, lakes, rivers, and oceans.
The water molecules on the surface of collected water (rivers, streams, oceans, mud puddles, etc..)evaporates, which means liquid water changes to a vapor (gas).
Water vapor is made up of individual water molecules that can move in any direction. These water molecules zip around and even bang into each other. But they generally bounce back and keep going.
Water vapor mixes with air. When this mixture rises to higher cooler altitudes (distance above earth) the zippy water vapor molecules lose energy and move slower. Those with enough energy continue to bounce around but at a slower speed. As the speed of the molecules decreases, instead of bouncing off each other they start sticking together forming cloud droplets. The change from water vapor to liquid water is called condensation.
Earth Science is the study of the Earth, which includes the atmosphere (air layer), lithosphere (solid materials-rocks), and hydrosphere (water-oceans, rivers, lakes,and streams)