tax collection vs aggregation

tax collection and aggregation both are nouns.

Word	Noun	Adjective	Verb	Adverb
tax collection	Yes	No	No	No
aggregation	Yes	No	No	No

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

Other hypernyms of tax collection include assembling, collecting, collection.

tax collection (noun)	aggregation (noun)
the collection of taxes	the act of gathering something together
	several things grouped together or considered as a whole