archipelago vs Bismarck Archipelago

archipelago and Bismarck Archipelago both are nouns.

Word	Noun	Adjective	Verb	Adverb
archipelago	Yes	No	No	No
Bismarck Archipelago	Yes	No	No	No

archipelago (noun)	Bismarck Archipelago (noun)
a group of many islands in a large body of water	a group of islands in the southwestern Pacific to the northeast of New Guinea; part of Papua New Guinea