Obviously to differentiate between the two we will have to define what constitutes as distilled water and purified water.
What is distilled water?
This type of water is created through a process called distillation; where the pure H2O is boiled out of its surrounding contaminants. These impurities that are found in water include dissolved and suspended solids like organic minerals. These types of contaminates that sit in water have tremendously high boiling points and even higher melting points. So how do you get rid of these impurities if the boiling point of water is only 100°C?
Well, the water along with its contaminants is boiled. The pure H2O turns into steam and then is caught and cooled leaving all the impurities behind. We now have distilled water. Wait, there is still a small issue – what about the organic compounds that have a lower boiling threshold than water like pesticides and other chemical compounds? Don’t worry as the water heats these compounds boil out of the water first, only after this pure water evaporates and is captured.
Now lets concentrate on purified water
Purified water must legally have reduced or removed impurities to extremely low levels. The impurity capacity of dissolved water in purified water cannot be higher than 10 parts per million. This in turn makes this type of water of a higher purity than spring, tap or even filtered water.
What makes purified water unique compared to filtered or spring water is due to the way in which it is cleansed. It is also put through additional purification processes like reverse osmosis, distillation and deionisation leading to the removal of virtually all types of impurities.
So what is the difference?
Surprise – distilled water is actually purified water! There are essentially no differences between the two types of water except that processes that they went through to reach purification.