A process that reverses, by the application of pressure, the flow of water in a natural process of osmosis so that the water passes from the more concentrated to the more dilute solution through a semipermeable membrane. It's a technical sounding title for something that's based on nature. Vegetation like trees, plants, and flowers use osmosis to draw water from the soil. Water in the soil (dilute solution) is drawn through plant cell membranes to the plant sap (concentrate solution). This process is osmosis.