The full form of RO is Reverse Osmosis. Reverse Osmosis is a filtration process that uses a semipermeable, porous membrane to remove impurities and large molecules from water. The process allows only clear water to pass through, removing unwanted ions, dissolved solids, TDS, and other pollutants. RO technology is primarily used for portable water production in water plants and factories. The final byproduct of the process is the solute. RO is often used in combination with other technologies such as UV and UF to provide comprehensive water purification.