A cell has a lot of dissolved sugars in it. Water surrounding the cell has fewer solutes. The movement of water into a cell because of differences in solute concentration inside and outside the cell is called osmosis. Osmotic potential is called As water enters a cell it swells and pressure increases in the cell because the membranes and wall enclosing the cell prevent the cell from expanding indefinitely. Pressure increases created by pressure is called Eventually the increase in pressure raises the potential to the point that it equals that of water outside the cell and there is no net uptake of water into the cell.
Water can still move in and out, but the rate is the same in either direction.
The water potential of a cell is the combination of the water potentials of osmosis and pressure. A cell that is fully swollen with water is said to be turgid . In wilted plants, cells have lost their turgidity. Growing plant cells require pressure from the cell to press on the cell wall to make it elongate as it is being formed. When young, expanding cells are not turgid, there is no pressure on the cell wall to make the wall elongate, it becomes thickened instead The thickening will actually make a plant stem or leaf stronger provided it does not occur for such a long period of time that there is damage to the growing cell.