How does osmosis and diffusion work across a cell membrane?

During osmosis, water molecules move across a cell membrane from an area of low solute concentration to an area of high solute concentration in order to balance the concentration of solutes on both sides of the membrane. Diffusion involves the movement of molecules from an area of high concentration to an area of low concentration across the cell membrane until equilibrium is reached. Both processes are passive and do not require energy input from the cell.