Question

Define osmosis in what two ways it is different from diffusion

Answer 1

Osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.

Diffusion can occur in any mixture, including one which includes a semipermeable membrane, while osmosis always occurs across a semipermeable membrane.

One big difference between osmosis and diffusion is that both solvent and solute particles are free to move in diffusion, but when we talk about osmosis, only the solvent molecules (water molecules) cross the membrane. 

Answer 2

osmosis is a process by which the solvent molecules tend to pass through a semipermeable membrane from a less conc. solution to a more conc. one
difference....
In osmosis only solvent particles can move whereas in diffusion both solute and solvent can move
in diffusion there is no role of semipermeable membrane whereas in osmosis it has major role