Differences between Diffusion and Osmosis are :
Diffusion occurs in all mediums - solid , liquids and gas whereas, Osmosis occurs only in the liquid medium.
Osmosis requires semi-permeable membrane whereas, diffusion does not restrict to semi-permeability.
Diffusion does not require water for the movement of the particles whereas, osmosis does reuire water for the movement of particles.
In diffusion , the flow of particles can occur in all directions wheras, in osmosis the flow of particles occurs only in one direction.