Okinawa vs Okinawa Island

Okinawa and Okinawa Island both are nouns.

Word	Noun	Adjective	Verb	Adverb
Okinawa	Yes	No	No	No
Okinawa Island	Yes	No	No	No

As nouns, Okinawa and Okinawa Island are synonyms defined as:

Okinawa and Okinawa Island: the largest island of the central Ryukyu Islands

Okinawa (noun)	Okinawa Island (noun)
a campaign in the closing days of World War II in the Pacific (April to June 1945); in savage close-quarter fighting United States marines and regular army troops took the island from the Japanese; considered the greatest victory of the Pacific campaign for the Americans	the largest island of the central Ryukyu Islands
the largest island of the central Ryukyu Islands