Final answer:
Osmosis is similar to simple diffusion in terms of the movement from high to low concentration, but differs in that it specifically refers to the movement of water across a semipermeable membrane.
Step-by-step explanation:
Osmosis is similar to simple diffusion in that both processes involve the movement of substances from an area of high concentration to an area of low concentration. In both osmosis and simple diffusion, the direction of movement is determined by the concentration gradient.
However, osmosis differs from simple diffusion in that it specifically refers to the movement of water molecules across a semipermeable membrane. While simple diffusion can occur with any type of substance, osmosis is specific to the movement of water.