Inferno vs Tartarus

Inferno and Tartarus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Inferno	Yes	No	No	No
Tartarus	Yes	No	No	No

As nouns, Tartarus is a hyponym of Inferno; that is, Tartarus 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
Tartarus: a place where the wicked are punished after death

Other hyponyms of Inferno include Gehenna, hellfire, red region.

Inferno (noun)	Tartarus (noun)
(Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment	a place where the wicked are punished after death