Spring, mineral and purified water are types of water. Spring water flows to the surface of the earth from an underground source, and mineral water retains a specified ratio of trace elements and mineral salts. Purified water is the result of cleansing processes such as reverse osmosis, distillation or deionization.
The U.S. Food and Drug Administration requires that bottled water products maintain their water type printed on their labels. Water qualifies as spring water if it either flows naturally from its repository or if bottlers have pulled it from the same source that feeds the natural spring. Mineral water must retain its original chemical composition and microbiological purity. Purified water must have emerged from purification processes that are suitable according to the standards of the United States Pharmacopoeia.