Sunda Islands vs archipelago

Sunda Islands and archipelago both are nouns.

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

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