copying vs duplication

copying and duplication both are nouns.

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

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

copying: an act of copying
duplication: the act of copying or making a duplicate (or duplicates) of something

Other hyponyms of copying include gemination, replication, reproduction, imitation.

copying (noun)	duplication (noun)
an act of copying	the act of copying or making a duplicate (or duplicates) of something
	a copy that corresponds to an original exactly