* Diffusion: This is the general movement of molecules or particles from an area of high concentration to an area of low concentration. It can happen in any medium, including liquids, gases, and even solids. Think of a drop of food coloring spreading throughout a glass of water.
* Osmosis: This is a *specific type* of diffusion, but only applies to the movement of water molecules across a semipermeable membrane (a membrane that allows some things to pass through but not others). Water moves from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration). Think of a cell surrounded by a membrane, where water moves in or out depending on the concentration of solutes inside and outside the cell.
Key differences:
* Type of movement: Diffusion applies to any kind of molecule; osmosis is specifically about water.
* Membrane: Osmosis requires a semipermeable membrane. Diffusion doesn't.
Let me know if you'd like more details on either of these processes!
