Final answer:
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. Osmosis is a special case of diffusion where water moves from an area of high concentration to an area of low concentration.
Step-by-step explanation:
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. It is a passive process of transport where substances move along the concentration gradient until equilibrium is reached. Osmosis, on the other hand, is a special case of diffusion where water moves from an area of high concentration to an area of low concentration.