Osmosis is a particular type of diffusion, it also a passive process and energy is not required.
The amount of solute in a aqueous solution is the concentration. Water potential is the pressure exerted by water molecules as they collide with a membrane or container. Its measured in units of pressure Pascals (Pa) or kilopascals (kPa). The symbol for water is the trident shape.
Pure water has a potential of 0kPa (at a standard temperature) this is the highest water potential. All other solutions have a negative water potential. When solutions of different concentrations are present there is different water potential, they are separated by a PARTAILLY permeable membrane.
Movement of water potential
There will be a net movement of water from the higher water potential solution (less concentrated) to the solution with more water potential (more concentrated) this will continue until the water potential is equal on both sides of the membrane. (Equilibrium)