The difference is not one of quality but of method. Filtration is selective: water passes through a medium that captures particular contaminants and lets the rest of the water and its minerals continue. Distillation is a phase change: the water is boiled off as steam, condensed back to liquid, and nearly everything that was dissolved in it is left behind in the boiler.
Filtration is selective, distillation is not
A carbon filter targets chlorine, taste, odor and many organic compounds. A sediment cartridge targets suspended particles by size. A specialist medium targets iron, or acidity, or lead. Each one is chosen for a named problem, and everything it was not chosen for goes straight through. Distillation makes no choices at all. Anything that will not evaporate and travel with the steam stays in the boiling chamber, which is why distilled water is so consistent and so slow to produce.
What survives each process
Filtered water keeps its dissolved minerals, keeps its taste, and keeps whatever the chosen medium was not designed to remove. Distilled water keeps almost nothing, though a few volatile organic compounds can carry over with the steam if the distiller has no carbon post-filter, which is why many units include one. Neither process is automatically safer. A filter matched to a tested problem can be a complete answer; a distiller run for water that had no problem is a slow, power-hungry way to make flat water.
Hard water shows the difference most clearly
Hardness is dissolved calcium and magnesium, and the USGS bands run from soft at 0 to 60 mg/L as calcium carbonate up through moderately hard at 61 to 120 and hard at 121 to 180. A standard carbon filter removes none of it, so filtered water still scales the kettle and still leaves your hair feeling coated. Distilling removes it completely but only a jug at a time. For a whole house, the answer is a softener, and our filtered shower head for hard water guide covers the smaller fix at one fixture.
Questions people ask about difference between filtered and distilled water
Is filtered water good enough for a steam iron?
Usually not. Ordinary filtration leaves the minerals in place and those minerals become scale on the element. Appliance manuals ask for distilled for that reason.
Does distilled water taste better than filtered water?
Most people say the opposite. Filtration removes the chlorine taste while keeping the minerals that give water body, whereas distilled water tastes noticeably flat.
Can a filter and a distiller be used together?
Yes, and better distillers do exactly that, running the condensed water through a carbon post-filter to catch anything volatile that traveled over with the steam.