archipelago vs Admiralty Islands

archipelago and Admiralty Islands both are nouns.

Word	Noun	Adjective	Verb	Adverb
archipelago	Yes	No	No	No
Admiralty Islands	Yes	No	No	No

archipelago (noun)	Admiralty Islands (noun)
a group of many islands in a large body of water	a group of islands in the Bismarck Archipelago