RO is an abbreviation for ‘reverse osmosis’, a process used to purify water by removing impurities and contaminants through a semi-permeable membrane. This method involves applying pressure to force water molecules through the membrane, leaving behind any dissolved solids and pollutants. RO is commonly used in household and industrial settings to produce clean and safe drinking water. It is also used in the production of various beverages and food products. The term ‘RO’ can also refer to the resulting purified water itself.