Hell isn’t in the Bible. At least not in the original languages.
Hell is an English word that Bible experts today use to translate a couple of Bible terms about eh afterlife: Gehenna and Tartaros.
Gehenna refers to a valley outside of Jerusalem where Jews once burned humans as sacrifices to a Canaanite god. By Jesus’ time, the name of this valley had become a symbol. Just as Sodom symbolized evil. Gehenna symbolized the terrible punishment that evil people could expect after God’s judgement. Jesus used this symbolism many times, for example: “If your hand causes you to sin, cut it off. It is better to enter heaven with only one hand than to go into the unquenchable fires of hell [Gehenna] with two hands: (Mark 9:43).
Tartaros appears only once in the Bible and refers to the place God will send rebels angels: “God did not spare even the angels when they sinned; he threw them into hell, in gloomy caves and darkness until the judgment day” (2 Peter 2:4).
Oddly, the original English word -hel-didn’t mean what it does today. It mean to cover or hide, and it generated related words like helmet and hole. But given how little we know about hell, the root word seems fitting.