concurrence vs overlap

concurrence and overlap both are nouns.

Word	Noun	Adjective	Verb	Adverb
concurrence	Yes	No	No	No
overlap	Yes	No	Yes	No

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

Other hyponyms of concurrence include concomitance, contemporaneity, contemporaneousness, unison.

concurrence (noun)	overlap (noun)
acting together, as agents or circumstances or events	a flap that lies over another part
the temporal property of two things happening at the same time	the property of partial coincidence in time
agreement of results or opinions	a representation of common ground between theories or phenomena
a state of cooperation

concurrence (verb)	overlap (verb)
	extend over and cover a part of
	coincide partially or wholly