Thank you for your question.
In the Bible Hell is the grave.
The Old Testament was written in Hebrew.
The Hebrew word translated ‘hell’ is ‘sheol’ which occurs some 65 times.
The AV translators translate it as ‘hell’ 31 times; ‘grave’ 31 times and ‘pit’ 3 times.
The word ‘sheol’ first appears in Genesis 37:
Genesis 37:35 And all his sons and all his daughters rose up to comfort him (Jacob); but he refused to be comforted; and he said, For I will go down into the grave unto my son mourning. Thus his father wept for him.
Jacob is clearly referring to the grave.
This confirms the sentence passed on Adam and his progeny in Genesis:
Genesis 3:19 In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return.
The New Testament was written in Greek.
Three different words are translated as ‘hell’.
‘Gehenna’ was the ‘valley of Hinnom’ (Hebrew ‘gey hinnom’), south of Jerusalem, where the filth and dead animals of the city were cast out and burned; it is a symbolic description of a rubbish dump.
In the Greek it is a transliteration of the Hebrew place name directly into Greek, the English translators, for no justifiable reason that I can discern, have chosen to translate it as ‘hell’ rather than transliterate the name as ‘Gehenna’ as the New Testament writers did.
It is translated ‘hell’ 12 times (3 times used in conjunction with the Greek ‘pur’ – fire)
Mt 5:22 But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger ofhellfire.
It is so translated in the following places: - Matthew 5:29,30;10:28:18:9;23:15;23:33; Mark 9:43,45,47; Luke 12:5; James 3:6
Hades in Greek (mythology) was the god who reigned over the dead in the underworld, the realm of the dead.
‘Hades’ is translated ‘hell’ 10 times and ‘grave’ once.
1Corinthians 15:55 O death, where is thy sting? Ograve, where is thy victory?
The other places where ‘hades’ is translated as ‘hell’ Matthew 11:23; 16:18; Luke 10:15; 16:23; Acts 2:27,31; Revelation 1:18; 6:8; 20:13.
‘Hades’ corresponds with the Hebrew ‘sheol’.
Acts 2:27 Because thou wilt not leave my soul inhell , neither wilt thou suffer thine Holy One to see corruption.
31 He seeing this before spake of the resurrection of Christ, that his soul was not left in hell, neither his flesh did see corruption.
Peter is quoting Psalm 16:
Psalm 16:10 For thou wilt not leave my soul in hell; neither wilt thou suffer thine Holy One to see corruption.
Peter’s explanation is that David is referring to Christ who was placed in a grave and raised from the dead before his body corrupted into dust.
2Peter 2:4 For if God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment;
‘Tartarus’ occurs once and is translated ‘hell’.
Tartarus in Greek mythology was the deepest region of the world; beneath the underworld itself. There was supposedly the same distance between Hades and Tartarus as between Heaven and earth. Tartarus was the deepest dungeon of Hades, where the mythical gods of Olympus confined their prisoners.
The parallel passage in Jude:
Jude 1:6 And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.
Peter and Jude are not speaking of angels of heaven but referring to the incident of Korah Dathan and Abiram. Leaders who rebelled against Moses.
Numbers 16:32 And the earth opened her mouth, and swallowed them up, and their houses, and all the men that appertained unto Korah, and all their goods.
33 They, and all that appertained to them, went down alive into thepit (sheol-grave), and the earth closed upon them: and they perished from among the congregation.
I suggest that Peter (not believing in Greek mythology) uses the word ‘tartarus’ because men are generally buried in relatively shallow graves (6 feet deep or so) but in the case of Korah and his men, when the earth opened they were swallowed much deeper into the ground than a normal burial.
Hell in Old English literature.
In defence of the translators, the word ‘hell’ at one time meant ‘to cover’ and was so used of the grave in the English language. We find in ancient English literature reference to the ‘helling’ of a house, meaning not the burning of the house, but the thatching of it. Similarly we read of the farmer ‘helling his potatoes’, the meaning of the expression being not the roasting of potatoes, but the putting of them into a pit and covering them for preservation from frosts, etc., until needed. Gradually this meaning has dropped out of the word.
I hope this helps