art collection vs accumulation

art collection and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
art collection	Yes	No	No	No
accumulation	Yes	No	No	No

As nouns, accumulation is a hypernym of art collection; that is, accumulation is a word with a broader meaning than art collection:

Other hypernyms of art collection include aggregation, assemblage, collection.

art collection (noun)	accumulation (noun)
a collection of art works	the act of accumulating
	several things grouped together or considered as a whole
	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
	an increase by natural growth or addition