Household water filters have become one of the common appliances in modern households, used to provide clean and safe drinking water. However, water filters are not "one size fits all". There are many types of filtration systems inside them based on different functions and technologies.

The following are several water filtration systems commonly used in hospitals: Reverse osmosis (RO) system Ultrafiltration (UF) system Deionized (DI) water system Activated carbon filtration system Ultraviolet (UV) disinfection system