Water, or H20, is a liquid that is found all over the Earth! Water can be in different states of matter: solids, liquids, and gases. Water vapor, or steam, is in the gas state of matter. When water is a liquid, the molecules in the water are flowing freely, but still have a definite size. As water heats up, it boils and turns into a gas called water vapor or steam. Check out the video at the bottom of this post! You can see the steam that is rising above the water. That is water, but in a gas state of matter. Water turns into water vapor because the molecules of water are moving apart from each other. They are floating in the air. The molecules take no definite size or shape. That is how water vapor is created!! Without evaporation, there would not be any rain! That is because the water evaporates and forms clouds. Then, the clouds get heavy and it rains!