Diffusion:
The physical process by which molecules of any substance move from a region of higher concentration (Pressure) to a region of lower concentration(pressure) through a membrane or freely until a homogeneous condition is achieved is known as diffusion.
Osmosis:
The movement of solvent molecules from a region of lower concentration to a region of higher concentration through a semipermeable membrane is known as osmosis.
Difference between Diffusion and Osmosis:
| Diffusion | Osmosis |
| 1. Movement of solid, liquid or gaseous molecules from a region of higher concentration or pressure to a region of lower concentration or pressure. | 1. The movement of solvent molecules from a region of lower concentration to a region of higher concentration through a semipermeable membrane. |
| 2. It can occur between any type of substance involving solid, liquid and gas. | 2. It occurs only between two liquids. |
| 3. It doesn't require any semipermeable membrane. | 3. It takes place only through a semipermeable membrane. |
| 4. It involves the movement of solute or solvent or gaseous molecules. | 4. Movement of only solvent molecules takes place. |