petting zoo vs collection

petting zoo and collection both are nouns.

Word	Noun	Adjective	Verb	Adverb
petting zoo	Yes	No	No	No
collection	Yes	No	No	No

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

Other hypernyms of petting zoo include accumulation, aggregation, assemblage.

petting zoo (noun)	collection (noun)
a collection of docile animals for children to pet and feed	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