Home water filtration systems operate through various mechanisms to remove or reduce contaminants. The most common types include activated carbon filters, reverse osmosis systems, and ion exchange filters. Activated carbon filters work by adsorbing contaminants onto the surface of the carbon, effectively trapping them. Reverse osmosis systems use a semi-permeable membrane to separate impurities from water, while ion exchange filters swap harmful ions with benign ones, such as replacing calcium and magnesium ions with sodium ions.