river vs Yellow River

river and Yellow River both are nouns.

Word	Noun	Adjective	Verb	Adverb
river	Yes	No	No	No
Yellow River	Yes	No	No	No

river (noun)	Yellow River (noun)
a large natural stream of water (larger than a creek)	a major river of Asia in northern China; flows generally eastward into the Yellow Sea; carries large quantities of yellow silt to its delta