"Hades was both the name of the ancient Greek god of the underworld (Roman name: Pluto) and the name of the shadowy place below the earth which was considered the final destination for the souls of the dead. Perhaps the most feared of the gods, he is described by both Homer and Hesiod as 'pitiless', 'loathsome', and 'monstrous' Hades. The god's wife was Persephone whom he abducted to join him in the underworld, and his symbol is a sceptre or cornucopia."
https://www.worldhistory.org/Hades/
"The phrase the “gates of hell” is translated in some versions as the “gates of Hades.” “Gates of hell” or “gates of Hades” is found only once in the entire Scriptures, in Matthew 16:18. In this passage, Jesus is referring to the building of His church: “And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it” (Matthew 16:18)."
https://www.gotquestions.org/gates-of-hell.html
"Jesus tells of how Lazarus was taken to “Abraham’s side,” a place of comfort and rest, while the rich man went to “Hades,” a place of conscious torment (Luke 16:22–23). Some Bible scholars believe that Jesus was telling a parable, that is, a fictional story not meant to be a literal account."
https://www.gotquestions.org/Lazarus-in-the-Bible.html
"13The sea gave up the dead who were in it, and Death and Hades delivered up the dead who were in them. And they were judged, each one according to his works. 14Then Death and Hades were cast into the lake of fire"
https://biblehub.com/nkjv/revelation/20.htm
"In the New Testament, Hades is the realm of the dead, and in this verse Hades or hell is represented as a mighty city with its gates representing its power."
https://www.gotquestions.org/gates-of-hell.html
"Some Christians take “the lower parts of the earth” as a reference to hell, where they say Jesus spent the time between His death and resurrection."
https://www.gotquestions.org/where-is-hell.html