Papua New Guinea vs capital of Papua New Guinea

Papua New Guinea and capital of Papua New Guinea both are nouns.

Word	Noun	Adjective	Verb	Adverb
Papua New Guinea	Yes	No	No	No
capital of Papua New Guinea	Yes	No	No	No

Papua New Guinea (noun)	capital of Papua New Guinea (noun)
a parliamentary democracy on the eastern half of the island of New Guinea; in 1975 it became an independent state within the Commonwealth of Nations	the administrative capital and largest city of Papua New Guinea