The main method of water purification is a combination of physical, chemical, and biological processes aimed at removing contaminants. Common techniques include filtration, chlorination, and reverse osmosis. Filtration removes larger particles, while chlorination disinfects and kills pathogens. Reverse osmosis is effective for removing dissolved solids and impurities. Depending on the source and intended use, additional processes, like ionic exchange, may also be employed. Effective water purification is crucial for ensuring safe drinking water and protecting public health from waterborne diseases.