Sheol

Sheol (Translated "Death") is the resting place for souls until they receive judgement.

Human Souls
Human souls receive judgement at death after the Great Ransom was payed, and this judgement is passed on the whether the payment was accepted or not. Those who accept the payment are received into Heaven. Those who do not are cast into Hell.

Other Souls
Thaeran souls are still kept in Sheol. On the Judgement Day, these souls will be judged on their service to God and either cast into the Pit or brought to Heaven. Hithpaelimic souls go to Purgatory first to be made into keruvim, so there are no hithpaelim in Sheol.

Nafwl souls who followed God will return to their Elder status, as they were before descending into bodies.

Only the dead can enter Sheol, and once inside they fall into a deep sleep; therefore, even resurrected Nephilim do not know what it looks like. No more is known about it.

The End of Time
It is assumed that, after God returned to the Triad to vanquish "death and hades," Sheol will be destroyed, as death will never come again.