Diffusion : Movement of solutes or ions from higher concentration to lower concentration is called as diffusion. It does not require energy therefore, it is called as passive transport.
Osmosis : The movement of solvent or water from higher concentration (solvent) to lower concentration (solvent) through a semipermeable membrane is called as osmosis Or the movement of solvent or water from lower concentration to higher concentration of solution through a semipermeable membrane is called as osmosis.
