So this is the introduction to the wonderful world of Linguistics and word etymology (it can be bland and boring, just a warning). Most of this is from memory, so let me know if I misremembered anything.
Hebrew / Greek / Germanic-Scandinavian / English
SHEOL / HADES / HEL / HELL
The words Sheol, Hades and Hel have approximately the same meaning and usage for their respective cultural-language groups, they are all referencing the underworld where souls go after death.
Curiously Sheol and Hel both have the grave as an entrance to the underworld. All the underworlds are down in the earth, beneath the ground.
Most modern translations will spell out "the grave" or "death" rather than use the Hebrew word Sheol in the Old Testament. The same is typical when the Greek word Hades is used in the New Testament, except substituted with Hell.
Now the English word Hell comes from the Germanic-Scandinavian Hel but only in spelling and pronunciation. The modern definition of Hell in English does not mean the underworld but a place of eternal burning torment.
The confusion comes from the multiple Greek words translated into the singular "Hell".
Hades is the underworld where souls go (divided up into Abraham's Bosom and the "pit"),
Tartarus is the Greek word used to describe the prison of the fallen angels from Genesis who procreated with humans (possibly mentioned as the "Abyss", the place the demons cast out by Jesus did not want to be sent to) This place is also in the earth underground, but apparently beneath Sheol in some sense literally or spiritually. (Tartarus is likely the same place as the Hebrew Abaddon based on Proverbs 15:11)
Gehenna is the Greek word used to describe the "lake of fire", place of eternal torment where Satan and his followers will be cast into. This place should be "empty" or not accessible yet, until the day of judgement.
Many of your modern English translations will take Hades+Tartarus+Gehenna=Hell. Hell will be used in place of all three words, this is partially due to the worldview at the time the KJV was translated in the 1600s.
However when using a literal or linear translation the wording is more transparent. Its important to keep in mind the Jews did equate "paradise" to Abraham's Bosom, which was a good place of rest for those who followed the Lord. whereas, "the pit", was the place of those who gave in to sin and evil. Both were still parts of Sheol (the underworld). This should be the context we view what Jesus described for Lazarus and the rich man. Neither place in the underworld is eternal.
What does this mean for us? it clarifies some of the arguments about what happened at the cross. Jesus descended to Hades (not Hell, hence why he conquered death AND "the grave", Sheol), he took the repentant thief on the cross down to Abraham's Bosom (Paradise in Sheol). This clears up the confusion of Jesus descending but still taking the thief to paradise (not heaven).
Based on the description in 1 Peter 3:18-20 Jesus likely went to the fallen angels and Nephilim spirits while in Sheol and by Tartarus. Probably to proclaim the beginning of the end for them based on descriptions in Jude and Rev.
...He was put to death in the body but made alive in the Spirit. 19 After being made alive,he went and made proclamation to the imprisoned spirits— 20 to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built.
At the end of days Sheol will disappear when all are raised and judged, those who sided with the Devil to the lake of fire Hell/Gehenna. Those who sided with YHWH to their reward.
