Different forms of bottled water may all qualify as H₂O, but they are not all suitable for the same purposes. There are actually a number of differences between distilled water and spring water, and some of these differences are significant, indeed. While spring water, drinking water, and artesian water are all bottled straight from the source, for instance, distilled water is processed from similar sources before bottling can take place.

One difference between distilled water and spring water is mineral content. Distilled water is the product of distillation, meaning the original water source has been converted into steam and then cooled down until it condenses into its final distilled form. This means heavy minerals and metals such as salt and iron do not generally survive the conversion to steam and are left behind as residue. Distilled water contains only scant traces of the minerals contained in natural spring water and other water sources.

There is also a definite difference in taste between distilled water and spring water. Because distilled water contains little to no minerals, many people find it to have a very astringent mouthfeel compared to spring water. Distilled water can be less satisfying than bottled spring water when used to rehydrate following or during exercise, primarily because it tends to draw essential minerals out of the body's tissues in order to restore the electrolyte balance. Spring water tends to have a "wetter" mouthfeel, which makes it a better choice to carry while exercising.

Many people use distilled water and spring water for different purposes. Distilled water is ideal for steam irons and steam cleaners because it does not contain the minerals and metals which cause rust or clogging. Some people also prefer to wash clothes in distilled water because it is considered purer than tap water or even spring water. Some dieters drink distilled water because of its alleged effects on the body's natural acidic levels and electrolyte balance. Distilled water can help restore a more alkaline blood chemistry and is free of impurities which can build up over months or years.

Spring water is generally used for re-hydration, cooking and beverage making. It may be more expensive than other forms of bottled water, but the taste of natural spring water is said to be superior to standard tap or drinking water, which may be distilled water enhanced with minerals. Spring water is rarely used in household applications such as steaming or sanitizing because the natural minerals are not removed during the bottling process. Spring water has simply been extracted from an underground source which has not reached the surface before bottling takes place.