collection vs accumulation

collection and accumulation both are nouns.

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

As nouns, collection and accumulation are synonyms defined as:

collection and accumulation: several things grouped together or considered as a whole

Other synonyms of collection include aggregation, assemblage.

collection (noun)	accumulation (noun)
the act of gathering something together	the act of accumulating
a publication containing a variety of works	several things grouped together or considered as a whole
request for a sum of money	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
several things grouped together or considered as a whole	an increase by natural growth or addition