Ellice Islands vs archipelago

Ellice Islands and archipelago both are nouns.

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

Ellice Islands (noun)	archipelago (noun)
a group of coral islands in Micronesia to the southwest of Hawaii	a group of many islands in a large body of water