Distilled water is a type of water that has had the majority of its impurities removed through a distilling process, which involves boiling the water and condensing the steam into a clean container. In chemistry and biology, there are some cheaper alternatives like deionized water, but distilled water is preferred because it offers more pure water. If you need exceptionally pure water, it can be double distilled. In a lot of situations and different fields, distilled water is used instead of tap water because of the absence of minerals. For example, distilled water is used in cooling systems on vehicles because the minerals and ions in tap water can cause corrosion to the engine’s components. It can also be used in aquariums, as it is preferred due to the absence of chemicals usually found in tap water. In order to distill water, you will need some sort of a distilling unit. Home water distillers can be bought at variety of stores.