retrieval vs ransom

retrieval and ransom both are nouns.

Word	Noun	Adjective	Verb	Adverb
retrieval	Yes	No	No	No
ransom	Yes	No	Yes	No

As nouns, ransom is a hyponym of retrieval; that is, ransom is a word with a more specific, narrower meaning than retrieval:

retrieval: the act of regaining or saving something lost (or in danger of becoming lost)
ransom: the act of freeing from captivity or punishment

Other hyponyms of retrieval include repossession, reclamation, deliverance, delivery, rescue, saving, recapture, retaking.

retrieval (noun)	ransom (noun)
the act of regaining or saving something lost (or in danger of becoming lost)	the act of freeing from captivity or punishment
the cognitive operation of accessing information in memory	payment for the release of someone
(computer science) the operation of accessing information from the computer's memory	money demanded for the return of a captured person

retrieval (verb)	ransom (verb)
	exchange or buy back for money; under threat