Absorb and Adsorb are two easily confused verbs which scientifically decribe different interactons.
Absorb
1. To swallow up.
2. To engross, or completely engage, the attention or faculties.
3. To suck in, drink in a fluid; to imbibe.
4. To take up by chemical or molecular action.
Absorption is essentially a macroscopic level effect.
Compare this with …
Adsorb
1. To undergo or cause to undergo a process in which a substance (often a gas) accumulates on the surface of a solid forming a thin film, often only one molecule thick. Mostly used in Chemistry and often descriptive of molecular level catalytic processes where a reaction is enhanced with one molecule sticking to the surface of the catalyst.
There is more than a subtle difference here. Note the use of the Latin prefixes ab- off, away, and ad- to, onto, towards.
Think of it this way in everyday terms: A sponge absorbs water, whereas a sticking plaster is adsorbed onto the skin. Alternatively, the man eats the pie (absorption) or the pie sticks to the man’s face (adsorption).