Deionized and Distilled Water is two types of water. The major difference between them is actually on various processes that lead to their preparation. Deionized water is water gotten through the process of deionization. This simply means it does not contain any form of ion because all the ions in it have been completely removed. Even different minerals in it are also removed. When you mix an electrically charged resin with water, all the cations and anions in it are removed when they attract with both the negative and positive ions of the resin.
Distilled water, on the other hand, is water which has been purified by distillation. Distilled water is gotten when you evaporate the water by boiling and allow it re-condense in another place. This process makes all the impurities that cannot be evaporated to remain, and therefore, we have pure water, although some particles that are volatile can also escape with the water. This means distilled water is not 100 percent pure.