In the Bible, Hell exists in four forms; Sheol, Tartarus, Abaddon, and Gehenna. All four are different kinds of places and all have been used interchangeably depending upon the version of the Bible you look at.
Sheol - it is the Jewish form of limbo. All souls are sent there. The Septuagint called it Hades in its translation of the Bible. There is no punishment in Sheol, Hades; instead everyone just tends to wander around. It is first mentioned in Genesis 37:35 "And all his sons and all his daughters rose up to comfort him; but he refused to be comforted; and he said, For I will go down to sheol to my son mourning. And his father wept for him." This is where Jacob was going to visit his supposedly dead son Joseph and it obviously means grave. In other places it means "pit" or a shallow depression into which a dead body is placed.
Another place it is used is in Deuteronomy 32:22 "For a fire is kindled in mine anger, and shall burn unto the lowest hell, and shall consume the earth with her increase, and set on fire the foundations of the mountains." In the Bible it is used 31 times as the word grave, 31 times as the word hell, and 3 times as the word pit, though the context of pit is used as a grave. Deuteronomy 32 describes this place as the modern concept of hell but at no time does it say anywhere in the Bible that the souls of the dead are sent to Sheol for punishment.
Job, my personal favorite book and should be the favorite of all atheists, describes it as a place of rest and that the wicked remain in that state of rest while heaven rewards those who are righteous. I could go into why I think it should be the favorite of all atheists here but I will stick to the topic at hand. If anyone is interested let me know and I'll post something about it.
Psalms uses it metaphorically as not so much a place but as a state of mind, a darkness of the mind without God and that anytime a person can be in Sheol while being alive.
Isaiah 5:14 Therefore hell (sheol) hath enlarged herself, and opened her mouth without measure: and their glory, and their multitude, and their pomp, and he that rejoiceth, shall descend into it. In context it is used as a parable or prose and not meant to be an actual place of punishment but to describe the grave such as when Jesus said, "For the wages of sin is death."
Tartarus - There are only a few Bibles that use the word Tartarus. The World English Bible uses it only once in 2 Peter 2:4 "For if God didn't spare angels when they sinned, but cast them down to Tartarus, and committed them to pits of darkness, to be reserved to judgment;" a place where the angels were sent after their sin, which is only described in the apocryphal books not accepted as God's word by most churches. It is a funny thing how they can blow off books of the Bible and yet still pull their beliefs from them. Tartarus was the Roman incarnation of Hell and like many other things Roman, (i.e. sacred rites of Mithraism, December 25th as a holiday, virgin births, etc.) Christians adopted it.
Abaddon - can be used as both the "angel of the bottomless pit," synonymous with Apollyon the Greek god Apollo who brings disease and famine, and for the word "destruction" when used to with the word "sheol" in prose. For example, death and destruction are often thrown together in modern times to describe mayhem or anarchy and the like, so to is sheol and abaddon which can mean "death and destruction."
And finally, before I put you to sleep, is Gehenna. This, by far, is the reference used to describe the Christian Hell. The word itself is modeled after a specific place on earth, the Valley of Hinmon, which was the local landfill where trash was burned. Mt 5:22 But I tell you, that everyone who is angry with his brother without a cause shall be in danger of the judgment; and whoever shall say to his brother, 'Raca,' shall be in danger of the council; and whoever shall say, 'You fool,' shall be in danger of the fire of gehenna (hell fire.) It depends upon the Bible you read as to where Gehenna is used since the word is translated into the word "hell" in many versions and is left as "Gehenna" in only a few. Most notable in the Old Testament is Jeremiah 19:2 "And go forth unto the valley of the son of Hinnom, which is by the entry of the east gate, and proclaim there the words that I shall tell thee,..." It is here that God describes the punishment of those who had worshipped false idols (Baal) but he doesn't say anything about the punishment occurring after death.
So where does the Christian concept come from? The concept of eternal punishment didn't really become popular until the third century BC and mostly, especially the Catholic version of it comes from Virgil's Aenid, a Hellenistic view of the after-life, the apocryphal book of Enoch, and the book "Paradise Lost" by John Milton, no not the guy from The Devil's Advocate, but the 17th century English Poet. It is obvious that Milton used much of the Aenid and the Book of Enoch to derive his fictional account but it was one of the more popular books during the 17th century since it outlined a belief in eternal punishment for the wicked and a layered system of hell. The Catholic belief of Purgatory comes from Milton and is contradicted in the Bible by Luke 16:19-28 "And beside all this, between us and you there is a great gulf fixed: so that they which would pass from hence to you cannot; neither can they pass to us, that would come from thence." Christians should remember what Jesus said about eternal damnation for sin after death, oh wait, he didn't say anything about it. In fact the words attributed to Jesus about hell can be translated into Gehenna, death, the grave and Sheol. None of which are attributed in the OT, Jesus' Bible, as a place for eternal suffering for the ungodly.