What is annihilationism? What is conditional immortality? Is hell eternal? Is the idea of eternal conscious punishment biblical?

Is annihilationism biblical? - https://www.gotquestions.org/annihilationism.html

What is conditional immortality? - https://www.gotquestions.org/conditional-immortality.html

How is eternity in hell a fair punishment for sin? - https://www.gotquestions.org/eternal-hell-fair.html

Previous podcast episode on annihilationism - https://youtu.be/XG8FQAtsVHw