hemisphere vs geographic region

hemisphere and geographic region both are nouns.

Word	Noun	Adjective	Verb	Adverb
hemisphere	Yes	No	No	No
geographic region	Yes	No	No	No

As nouns, geographic region is a hypernym of hemisphere; that is, geographic region is a word with a broader meaning than hemisphere:

Other hypernyms of hemisphere include geographic area, geographical area, geographical region.

hemisphere (noun)	geographic region (noun)
either half of the cerebrum	a demarcated area of the Earth
half of the terrestrial globe
half of a sphere