| S. No | Adsorption | Absorption |
| (i) | It is a surface phenomenon i.e., occurs only at the surface of the adsorbent. | It is bulk phenomenon i.e., occurs throughout the body of the material. |
| (ii) | Concentration of the adsorbate at the adsorbent surface is more than in the bulk. | Absorbed material is uniformly distributed throughout the bulk. Concentration is same throughout. |
| (iii) | Rate of adsorption is rapid initially and decreases later. | Absorption occurs with uniform rate. |
| (iv) | Example: Water vapour on silica gel. | Example: Water vapours are absorbed by anhydrous CaCl2 . |
