coin collecting vs collection

coin collecting and collection both are nouns.

Word	Noun	Adjective	Verb	Adverb
coin collecting	Yes	No	No	No
collection	Yes	No	No	No

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

coin collecting: the collection and study of money (and coins in particular)
collection: the act of gathering something together

Other hypernyms of coin collecting include aggregation, assembling, collecting.

coin collecting (noun)	collection (noun)
the collection and study of money (and coins in particular)	the act of gathering something together
	a publication containing a variety of works
	request for a sum of money
	several things grouped together or considered as a whole