Distilled water and drinking water are not two grades of the same product. Drinking water is simply water fit to drink, still carrying its dissolved minerals; distilled water has been boiled to steam and condensed back to liquid, leaving nearly everything dissolved behind in the boiler. That single difference decides what each one is good for in a house.
What each label actually means
Drinking water is a description of fitness, not of process. It may be treated municipal water, spring water or reverse osmosis water, and it still carries dissolved calcium, magnesium, sodium and bicarbonate. Distilled water is defined by the process instead: the water is boiled, the steam is collected and cooled, and salts, metals and most heavy compounds stay behind. Two bottles can both be perfectly safe and still be nothing alike chemically.
Where distilled water earns its place
Buy distilled for machines rather than for the family. A steam iron, a room humidifier, a CPAP reservoir, a garment steamer or a lead-acid battery all run better on water with nothing dissolved in it, because there is no mineral left to bake onto a heating element or block a fine jet. For daily drinking and cooking, most households do better treating the supply they already pay for, since a jug habit costs money every week and changes nothing at the tap.
If you are comparing these because the tap tastes wrong
Switching to bottled distilled water is a workaround, not a diagnosis. Start with what is actually in the supply. Every community water system publishes an annual Consumer Confidence Report and the EPA maintains a finder for it, so you can read your own utility's results before spending anything. Once you know whether the complaint is chlorine, hardness or something else, our best filter for drinking water guide points at the right cartridge instead of a delivery habit.
Questions people ask about distilled vs drinking water
Is distilled water safer than ordinary drinking water?
Not automatically. Distillation removes dissolved minerals and most contaminants, but treated tap water that meets standards is also fit to drink. The flat taste is the difference most people actually notice.
Can I put drinking water in a steam iron?
You can, but the mineral in it turns into scale inside the iron and eventually spits white flecks onto fabric. That is why appliance manuals ask for distilled water.
Does a home filter turn tap water into distilled water?
No. Filters, and even reverse osmosis units, reduce selected contaminants without boiling and condensing the water, so the result is filtered water rather than distilled water.