Water is the only substance on Earth that exists simultaneously in nature as a solid, a liquid, and a gas Liquid is the most common of water's states and is the form that is generally denoted by the world "water Water is found on Earth as oceans, lakes, groundwater, rivers, and in other forms Solid water is water that is frozen and found largely as glaciers at both north and south poles In many places in the world, when the air temperature is less than zero degrees Celsius, water takes the form of snow Water is a gas when it is in the atmosphere as vapor or steam a great amount of it in the air may take the form of clouds.