North America vs collection

North America and collection both are nouns.

Word	Noun	Adjective	Verb	Adverb
North America	Yes	No	No	No
collection	Yes	No	No	No

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

Other hypernyms of North America include accumulation, aggregation, assemblage.

North America (noun)	collection (noun)
the nations of the North American continent collectively	the act of gathering something together
a continent (the third largest) in the western hemisphere connected to South America by the Isthmus of Panama	a publication containing a variety of works
	request for a sum of money
	several things grouped together or considered as a whole