Book of Revelation
The Book of Revelation (formal title The Revelation of St. John the Divine, also called The Revelation to John, The Apocalypse of John, or simply Revelation) is the final book of the Christian Bible (The New Testament). It records a series visions received by the apostle John while he was imprisoned on the island of Patmos. The visions describe the end times and the second coming of Jesus Christ. (Preterists disagree, believing the book describing events fulfilled at other points in history.)
Four Horsemen of the Apocalypse
Revelation first describes the arrival of the Four Horsemen of the Apocalypse: Pestilence, War, Famine, and Death. However, the Bible itself only directly one horseman, "death".
Mark of the Beast
Revelation describes a time in which the a mark consisting of the Number of the Beast will be required on all people in order to buy or sell.
Twenty-one judgements are pronounced on the earth: the seven Seal Judgements, the seven Trumpet Judgements, and the seven Bowl Judgements.