Answer:
Distilling water traditionally refers to heating water in a container until it releases vapor that condenses on a cool smooth surface away from the main body of water. This condensation should be pure H2O, as only the water itself converts to vapor and leaves all impurities in the container the water started in. Distilled water often tastes funny because people are used to water with various levels of minerals/chlorine/metals that do not transfer with the water vapor through the distilling process. Some people interpret this complete lack of flavor as bitter or metallic.
A Bunsen burner, a beaker, some coiled copper tubing, and another beaker are all you need to make distilled water at home.