Water exists in many forms including water vapor, liquid, and ice, all of which are found on Earth including atmospheric moisture, precipitation, soil moisture, groundwater, ice, snow, oceans, and seas; within plants and animals; in lakes, streams, and rivers; and in man-made reservoirs. Water cycles between these forms both visibly, as when atmospheric [Page 217]moisture falls as rain, and invisibly, as when precipitation seeps into the soil to become groundwater. Water makes up 70 percent of the Earth's surface. Most of the water is contained in the oceans, with only a small percentage available as freshwater, most of which is frozen in glaciers.