precondition vs requirement

precondition and requirement both are nouns.

Word	Noun	Adjective	Verb	Adverb
precondition	Yes	No	Yes	No
requirement	Yes	No	No	No

As nouns, requirement is a hypernym of precondition; that is, requirement is a word with a broader meaning than precondition:

Other hypernyms of precondition include prerequisite.

precondition (noun)	requirement (noun)
a condition that is a prerequisite	something that is required in advance
an assumption that is taken for granted	required activity
an assumption on which rests the validity or effect of something else	anything indispensable

precondition (verb)	requirement (verb)
put into the required condition beforehand