Japanese Archipelago vs Japanese Islands

Japanese Archipelago and Japanese Islands both are nouns.

Word	Noun	Adjective	Verb	Adverb
Japanese Archipelago	Yes	No	No	No
Japanese Islands	Yes	No	No	No

As nouns, Japanese Archipelago and Japanese Islands are synonyms defined as:

Japanese Archipelago and Japanese Islands: a string of more than 3,000 islands to the east of Asia extending 1,300 miles between the Sea of Japan and the western Pacific Ocean

Other synonyms of Japanese Archipelago include Japan.

Japanese Archipelago (noun)	Japanese Islands (noun)
a string of more than 3,000 islands to the east of Asia extending 1,300 miles between the Sea of Japan and the western Pacific Ocean	a string of more than 3,000 islands to the east of Asia extending 1,300 miles between the Sea of Japan and the western Pacific Ocean