duplication vs twin

duplication and twin both are nouns.

Word	Noun	Adjective	Verb	Adverb
duplication	Yes	No	No	No
twin	Yes	Yes	Yes	No

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

Other hyponyms of duplication include backup, computer backup, counterpart, similitude, match, mate.

duplication (noun)	twin (noun)
the act of copying or making a duplicate (or duplicates) of something	a duplicate copy
a copy that corresponds to an original exactly	either of two offspring born at the same time from the same pregnancy

duplication (adjective)	twin (adjective)
	being two identical

duplication (verb)	twin (verb)
	give birth to twins
	grow as twins
	bring two objects, ideas, or people together
	duplicate or match