geographical region vs The Maritimes

geographical region and The Maritimes both are nouns.

Word	Noun	Adjective	Verb	Adverb
geographical region	Yes	No	No	No
The Maritimes	Yes	No	No	No

geographical region (noun)	The Maritimes (noun)
a demarcated area of the Earth	the collective name for the Canadian provinces of New Brunswick and Nova Scotia and Prince Edward Island