Inferno vs red region

Inferno and red region both are nouns.

Word	Noun	Adjective	Verb	Adverb
Inferno	Yes	No	No	No
red region	Yes	No	No	No

As nouns, red region is a hyponym of Inferno; that is, red region is a word with a more specific, narrower meaning than Inferno:

Inferno: (Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment
red region: a place of eternal fire envisaged as punishment for the damned

Other hyponyms of Inferno include Gehenna, Tartarus, hellfire.

Inferno (noun)	red region (noun)
(Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment	a place of eternal fire envisaged as punishment for the damned