Main article: The Shinobi World The earth is where all the living and the mortals live until it is time for them to die.
Main article: Chaos The realm ruled by Inferno, otherwise known as Soul Edge. It is the realm where the wicked are punished. It is a desolate, flamy, volcanic area also known as Chaos. Echo Uchiha appears to be some sort of "contract" conecting Hell with the Living World, Earth.
Main article: Other World The Spirit World is the realm also called Heaven which is ruled by the goddess, Ha, which is overruled by Saitatsu. It is where the kind of heart go to live in their afterlife.
The Three Divine Kingdoms
Planet of the Kais
The Kais and the Grand Kai live here but the Supreme Kais live in another Realm.
The Terrestrial Kingdom, or known as the "Middle Heaven" is where the Supreme Kais reside. The only other people allowed here was Rokudou Sennin, Hikaru Kurosaki, Sasori Rilenyth, and Byakko Kurohitsugi, who all studied under him. Seireitou Hyuga is also allowed during his training with Rokudou.
The Celestial Kingdom, or the "Highest Heavens" is somewhere reserved for Yhvh (God) and the Gods of Creation, which are the weilders of the Blades of Absolute Creation: Seireitou Hyuga, Haizo Hyuga, Minkai Zokatakei. When they evolve into Gods, they reside in their respective Kingdoms and rules over all of existance.
Supreme Planet of the Kais
This is where the Supreme Kais and the Grand Supreme Kai reside.