During the distillation of the water, the gases dissolved in it escape. The dissolved substances (ions) remain as solid residue in the distillation vessel. The water obtained in the receiver (Latin: aqua destillata) has a degree of purity, which is sufficient for most purposes in the laboratory or plant. The escaped gases partly dissolve again in the distillate, so you can find cyanide or chlorine(id) in it, depending on the composition of the starting mixture.
In electroplating, “distilled water” is not used, not only because it is too expensive, but also because it is possible to use other ways, e.g. with ion exchangers, disturbing anions and cations. The Wisely treated water is also called deionized water or “deionized” or “demineralized” water. The purity content of this water is sufficient in most cases for the respective use in electroplating.