Both elements are found in abundance in the universe. Under extreme heat and pressure, these elements can be combined to form water. These conditions were present when the rocks that formed our planet collided. Hence, the water on earth was formed while the planet was forming. Water on the earth is found in all three states.
Solid water is known as ice, and gaseous water is known as vapor.
Primarily, organisms use water in its liquid or aqueous form. Water has some interesting physical properties that have consequences for life. Water is most dense when it is at about 4 C, and it is considerably less dense as ice. This means that water expands when it freezes, and it also floats on liquid water. Because most fluids in organisms are primarily water, freezing can cause extensive damage.