archipelago vs Sunda Islands

archipelago and Sunda Islands both are nouns.

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

archipelago (noun)	Sunda Islands (noun)
a group of many islands in a large body of water	a chain of islands in the western Malay Archipelago