Lakes and ponds are inland bodies of water. Ponds tend to be shallow and small, and most do not have names. Lakes, on the other hand, vary greatly in size, and most do have names. Lake Superior, for example, which lies between Canada and the United States, has the greatest surface area of any freshwater lake in the world—31,820 square miles (82,732 square kilometers). Lake Baikal in southern Siberia is the deepest at 1 mile (1.6 kilometers). Baikal also holds the most water—more than Lake Superior, even though it's surface area is less than half that of Superior. Ponds and lakes also differ in overall water temperature. Ponds have a uniform...