They will be taken from this place we call Earth to be with their Maker in heaven.
Non-believers will be left behind and would have to face the tribulation.
Believers cannot agree with the timing of the rapture except that it will happen. There are several sites which try to explain the different kinds of rapture, here is one of them.
Left Behind The Movie
Left Behind: (2000) Full Movie Video
The Biblical prophecy of Armegeddon begins when the Rapture instantly takes all believers in Christ from the Earth. A reporter left behind learns that the Anti-Christ will soon take power.
Director: Vic Sarin
Stars: Kirk Cameron, Brad Johnson, Janaya Stephens