chain of mountains vs Appalachian Mountains

chain of mountains and Appalachian Mountains both are nouns.

Word	Noun	Adjective	Verb	Adverb
chain of mountains	Yes	No	No	No
Appalachian Mountains	Yes	No	No	No

chain of mountains (noun)	Appalachian Mountains (noun)
a series of hills or mountains	a mountain range in the eastern United States extending from Quebec to the Gulf of Mexico; a historic barrier to early westward expansion of the United States