A cartridge filter is a crucial component used in various filtration systems to remove contaminants from liquids or air. It consists of a replaceable filter element enclosed in a cylindrical housing. Cartridge filters come in different types, including sediment, activated carbon, polypropylene, ceramic, and HEPA, each designed for specific filtration needs. They are valued for their high filtration efficiency, ease of maintenance, and versatility across applications such as water filtration, air purification, and industrial processes.