No. Purified water is a category defined by the result, water with almost all dissolved solids removed, no matter which process removed them. Distilled water is one specific method of getting there, by boiling water and condensing the vapor. So all distilled water is purified water, while most purified water on sale or made at home was produced by reverse osmosis or deionization instead.
Purified describes an outcome
When water is described as purified, the claim is about how little remains dissolved in it, not about how it got that way. Reverse osmosis, distillation and deionization all reach that standard by completely different routes: a membrane that rejects dissolved solids, a phase change that leaves them behind in the boiler, and a resin bed that exchanges ions away. Filtered water is a different claim entirely and a much weaker one, since a filter that removes chlorine and sediment leaves every dissolved mineral in place. That is why filtered and purified are not interchangeable words even though the marketing often treats them as if they were.
Distillation describes a process
A distiller boils the water and condenses the steam in a separate chamber. Minerals, salts and most heavy metals do not evaporate, so they stay in the boiling vessel as scale that you scrub out. Any contaminant that boils at a lower temperature than water, such as certain volatile organic compounds, can carry over with the steam, which is why household distillers usually pass the condensate through a small carbon cartridge before it reaches the collection jug. Distillation is thorough and slow, uses a lot of energy for the volume produced, and needs the boiler descaled regularly, which is why it survives as a countertop appliance rather than a house-wide system.
What the difference means in a home
For drinking, both taste similarly flat because both have had the dissolved calcium and magnesium removed. The USGS defines hardness as dissolved calcium and magnesium, measured as calcium carbonate, and both processes take it to almost nothing, which is why a remineralizing stage is a common addition on reverse osmosis systems. For appliances that specify distilled water, such as steam irons and some humidifiers and medical devices, follow the manufacturer's instruction rather than substituting: RO water is usually close enough in practice, but the appliance warranty may name distilled specifically and that is a contractual point rather than a chemical one.
Which one to make at home
If the goal is good drinking and cooking water for a household, reverse osmosis is almost always the better choice: it produces far more per day, needs no electricity in a conventional under-sink build, and requires cartridge changes rather than descaling. Distillation earns its place where the volume is small, the requirement is specifically for distilled water, or there is no plumbing to tee into. Neither addresses hardness in the rest of the house, so if scale on the fixtures is the complaint, a softener is the correct purchase and neither of these is a substitute for it.
Questions people ask about is purified water the same as distilled water
Is reverse osmosis water considered purified?
Yes. Purified describes the outcome rather than the method, and RO removes the great majority of dissolved solids, so its output falls into the purified category.
Can I use RO water where distilled is specified?
Usually it works in practice, since both have very low dissolved solids. Check the appliance instructions first, because a warranty naming distilled water is a contractual matter, not a chemical one.
Why does purified water taste flat?
Taste comes largely from dissolved minerals, and both distillation and reverse osmosis remove nearly all of them. A remineralizing cartridge puts back a small measured amount to restore body.
Does distilled water remove hardness?
From the distilled water itself, yes, since the USGS defines hardness as dissolved calcium and magnesium and neither evaporates. It does nothing for hard water anywhere else in the house.