The difference between Absorb and Drink in

When used as verbs, absorb means to include so that it no longer has separate existence, whereas drink in means to absorb (liquid).

check bellow for the other definitions of Absorb and Drink in

Absorb as a verb (transitive):

To include so that it no longer has separate existence; to overwhelm; to cause to disappear as if by swallowing up; to incorporate; to assimilate; to take in and use up.
Absorb as a verb (transitive, obsolete):

To engulf, as in water; to swallow up.
Absorb as a verb (transitive):

To suck up; to drink in; to imbibe, like a sponge or as the lacteals of the body; to chemically take in.
Absorb as a verb (transitive, physics, chemistry):

To take in energy and convert it, as in receiving a physical impact or vibration without recoil. in receiving sound energy without repercussion or echo. taking in radiant energy and converting it to a different form of energy, like heat.

Examples:

"Heat, light, and electricity are absorbed in the substances into which they pass."
Absorb as a verb (transitive):

To engross or engage wholly; to occupy fully
Absorb as a verb (transitive):

To occupy or consume time.
Absorb as a verb (transitive):

Assimilate mentally.
Absorb as a verb (transitive, business):

To assume or pay for as part of a commercial transaction.
Absorb as a verb (transitive):

To defray the costs.
Absorb as a verb (transitive):

To accept or purchase in quantity.

Drink in as a verb (transitive):

To absorb (liquid).

Examples:

"The dry land drank in the rain."
Drink in as a verb (transitive, figurative):

To absorb; to be completely attentive to.

Examples:

"They listened to him in rapt silence, drinking in his every word."

"I like to walk in the hills and drink in the wonderful views."