The three states of water are solid, liquid and gas. The solid state of water is ice, and the gaseous state of water is water vapor.
Liquid water becomes solid ice at 32 degrees Fahrenheit. When liquid water becomes ice, the water molecules form rigid ice crystals. When liquid water freezes, it expands and becomes less dense. The density of ice is lower because there is more open space between the water particles than in water.
When water is in gaseous form, the particles freely move and are unconfined. The most common source of water vapor is the evaporation of liquid water. Some water vapor is also formed through sublimation, the conversion of solid ice directly to water vapor.