archipelago vs Solomon Islands

archipelago and Solomon Islands both are nouns.

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

archipelago (noun)	Solomon Islands (noun)
a group of many islands in a large body of water	the southern Solomon Islands that since 1978 form an independent state in the British Commonwealth
	the northernmost islands are part of Papua New Guinea; the remainder form an independent state within the British Commonwealth