Reverse osmosis (RO) is a water purification process that uses a partially permeable membrane to remove ions, unwanted molecules and larger particles from drinking water. Reverse osmosis differs from filtration in that the mechanism of fluid flow is by osmosis across a membrane.
The water coming out of your tap may contain various contaminants. There’s at least one chemical or contaminant in your water, whether it’s chlorine from treatment, salt from the environment. Most of theses contaminants won’t cause problems for washing your dishes, or even bathing, but you certainly don’t want to drink them.
The countertop reverse osmosis system fits to your tap and the water runs through the system to purify as it comes out.