In Orthodoxy hell (gehenna fire) is reserved for death itself, and its cronies, from satan and the antichrist to the truly evil, after the second coming.
All who die enter into hades. Jesus told the repentant thief ,"TODAY, you will be with me in paradise. Yet Jesus went to Hades for 3 days. Paradise, place of comfort, third heaven, Abrahams bossom,tartarus are all the same.
Hamartia the greek word for sin means "missing the mark". The more you miss the mark the further you seperate yourself from the Light. And the further you are from the divine Light, the darker it is.
The parable of the rich man and Lazarus is good to study, Luke 16.19-31. Lazarus was carried off to Abraham's(type for God) bossom, meaning he was extremely close to God, so close in fact that it is characterized as being in his bossom. The rich man in hades on the other hand, could see Abraham but from afar. Another words his seperation was great.
The gulf (Lk 16.26) is the amount of seperation between the rich man and God. The rich man is actually not that bad off, he can still see and interact with the Light, other parts of scripture refer to being cast out in outer darkness (Matt8.12) and, "is reserved the blackness of darkness"(2 Pet 2.17)