Hell

"Hell is not a second Heaven. It's not a less-pleasant alternative, like you humans like to think. You won't see your friends there. Or your enemies, for that matter. You won't see anyone. It'll just be mindless, lonely, hopeless agony for eternity. And each second there feels like a decade on Earth."

Nature
Hell, or the Pit, is the second-lowest of dimentions, only being above the Abyss. It is a place of utter torment, the only place to exist completely devoid of God's presence. Nothing good exists there. It was made after Sattanael's rebellion to accomodate the Demons after the Great and Terrible Day, but it was also decreed that the enemies of God, all those who did not follow Him with all their hearts, would be thrown there as well after being judged. It's opposite is Heaven, where the glory of God exists in full.

It was refered by a few of the Apostles as the Lake of Fire, and that description is canon with that of the demons.

Inhabitants
Unlike modern beliefs, Hell is not where the demons call home. It is torment for them, too. Demons defeated by angels are sent there, but they can escape. However, after judgement they will be cast in one final time and the Pit will be locked, allowing no more to escape for eternity.

After the Great Ransom was payed, the human souls in Sheol were brought forth and either brought to Heaven or sent to Hell. Those who fell to the Pit are there until the End of Time, where they will be locked in there forever. Until then, however, the Pit is open and though they cannot escape on their own, they can be brought out for a short time by the Artifacts, though these spirits are not returned to a body.

Thaeran spirits are kept in Sheol until the judgement, where they will be cast into Hell or brought to Heaven, depending on their deeds and the deepest desires of their heart.