A water purifier is a machine used to remove impurities, harmful chemicals, and microorganisms from water to make it safe for drinking and other uses. It is commonly used in homes, offices, and industries to improve water quality. The purifier usually consists of several filtration stages such as a sediment filter (to remove dirt and sand), an activated carbon filter (to remove odor, chlorine, and chemicals), and advanced systems like UV (ultraviolet) sterilization or RO (reverse osmosis) membranes to eliminate bacteria and dissolved salts.

In operation, water enters the purifier and first passes through the sediment filter, where large particles are removed. It then flows through the carbon filter to improve taste and remove chemical impurities. In advanced systems, the water is forced through a fine membrane (RO), which removes very small contaminants, including dissolved solids. After that, UV light or other disinfection methods kill remaining bacteria and germs. The purified water is then stored in a tank or dispensed directly for drinking, providing clean and safe water for use.