The Full form of RO is Reverse Osmosis. It is a process by which RO water purifier remove ions, unwanted molecules, TDS, and dissolved solids from the water. Reverse Osmosis (RO) is the opposite of Osmosis. In Osmosis, solvent passes to a more concentrated solution through a semi-permeable membrane from a less concentrated solution. In RO, the solvent passes from a more concentrated solution to a low concentrated solution (in the opposite direction) through the semi-permeable membrane.

The pressure required is generated by the pump of the RO water purifier to move solvent water from more concentration solution (tap water) to low concentration solution (purified water). RO is a water treatment process that removes all the contaminants from water by using pressure to force water molecules through a semi-permeable membrane. The contaminants are thus filtered out and flushed away during this process, leaving clean and delicious drinking water.

RO process removes lead from water and ultimately protects the people from many diseases such as nerve damage, high blood pressure, and low fertility. Drinking RO water is also helpful in eliminating risks of anaemic conditions, and brain damage especially in children. RO is the most effective and convenient method of water filtration. It is the same filtration that was first designed to desalinate seawater.