co-occurrence vs coincidence

co-occurrence and coincidence both are nouns.

Word	Noun	Adjective	Verb	Adverb
co-occurrence	Yes	No	No	No
coincidence	Yes	No	No	No

As nouns, co-occurrence and coincidence are synonyms defined as:

co-occurrence and coincidence: the temporal property of two things happening at the same time

Other synonyms of co-occurrence include concurrence, conjunction.

co-occurrence (noun)	coincidence (noun)
the temporal property of two things happening at the same time	the temporal property of two things happening at the same time
an event or situation that happens at the same time as or in connection with another	the quality of occupying the same position or area in space
	an event that might have been arranged although it was really accidental