Yes, this is true that Osmosis is a special kind of diffusion’. In both osmosis and diffusion, there is a movement of particles from a region of higher concentration to that of a lower concentration. However, in the case of ‘Osmosis,’ the solvent molecules pass through a semipermeable membrane from a dilute solution to more concentrated solution.
Examples:
Osmosis: Water flowing across the plasma membrane
Diffusion: Spraying perfume in a room