Ultra-pure water is water produced by the US scientific and technological community in order to develop ultra-pure materials (semiconductor original materials, nano-fine ceramic materials, etc.) using distillation, deionization, reverse osmosis technology or other appropriate supercritical fine technology. Except for water molecules (H20), there are almost no impurities, no bacteria, viruses, chlorinated dioxins and other organic matter. Of course, there are no mineral trace elements needed by the human body. Ultra-pure water has no hardness and tastes sweeter. It is called soft water and can be drunk directly or boiled.
Ultra-pure water is a degree that is difficult to achieve with general technology. If the resistivity of water is greater than 18MΩ*cm (without obvious boundaries), it is called ultra-pure water.