Those people who adopt the Post Tribulation Rapture position believe that Jesus Christ will return for His children immediately after, or sometime after the Great Tribulation has ended, as opposed to those Christians who believe that He will return some time before the Great Tribulation begins, or some time while the Great Tribulation is still in progress. For reasons which are fully explained in his in-depth series,
The Great Tribulation And The Rapture, Bill Kochman currently believes that the Post-Tribulation Rapture is the most Scripturally-sound view of the various Rapture positions. Please read this in-depth series for a more-detailed explanation concerning his views.