This document discusses water used in pharmaceutical manufacturing. It outlines several types of water (potable, purified, water for injection) and their specifications and production methods. Purified water is used for non-parenteral preparations and equipment cleaning, while water for injection has more stringent endotoxin limits for use in parenteral products. Various treatment techniques are described like demineralization, reverse osmosis, and ultrafiltration. Proper water treatment, storage, and validation are essential to ensuring high quality water suitable for pharmaceutical applications.