It means the end of the world, but first a great tribulation where the beast will wear out and overcome the saints, persecuting and killing many who do not worship the beast and will not accept the mark. It means a one world government, fractious, that breaks apart and consumes the whore who rides the beast (Vatican), and a war that consumes a quarter of the earth's population. It means plagues and meteor impacts, the death of much wildlife, the poisoning of much of the sea and the locusts tormenting people who take the mark. It means much death until the everyone who will ever come to Christ has come to Him. Then, and only then will the Son of Man return and wreck the wicked.

Whether He is physically present, as described in Matthew 24, or He rules through spiritually influencing the saints (described in Revelation 20 but not ruling out a physical presence) is somewhat unimportant from our place. He will rule for 1000 years.

After a millenia, Satan will rebel and gather his armies and beseige the saints only to be destroyed by Heavenly fire and finally cast into the lake of fire and brimstone.