Answer: Osmosis is different from diffusion in that whereas osmosis occurs only through a semipermeable (selectively permeable) membrane, diffusion can occur in any medium whether a semipermeable or not.
Explanation: Osmosis is the movement of solvent molecules from a dilute solution to a more concentrated solution through a semi permeable membrane, that is from an area of high solvent concentration to an area of low solvent concentration through a semi permeable membrane.
Diffusion is the movement of substances from an area of higher concentration to a region of lower concentration.
Osmosis occurs only in a semi permeable membrane while diffusion occurs in any medium.
Both osmosis and diffusion are examples of passive transport process and both aim at achieving equal concentration between two solutions.