The word eschatology derives from two Greek roots meaning "last" (ἔσχατος) and "study" (-λογία) – involves the study of "end things", whether of the end of an individual life, of the end of the age, of the end of the world, or of the nature of the Kingdom of God.
death and the afterlife, Heaven and Hell, the Second Coming of Jesus, the resurrection of the dead, the rapture, the tribulation, millennialism, the end of the world, the Last Judgment, and the New Heaven and New Earth in the world to come.
"Blessed and holy is he who has part in the first resurrection. Over such the second death has no power" [Rev 20:6].