Great Barrier Reef vs Australia

Great Barrier Reef and Australia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Barrier Reef	Yes	No	No	No
Australia	Yes	No	No	No

Great Barrier Reef (noun)	Australia (noun)
the largest coral reef in the world; in the Coral Sea off the northeastern coast of Australia	a nation occupying the whole of the Australian continent; Aboriginal tribes are thought to have migrated from southeastern Asia 20,000 years ago; first Europeans were British convicts sent there as a penal colony
	the smallest continent; between the South Pacific and the Indian Ocean