Quick summary on Judgments and when they occur
-Those who hold an Amillennial or Postmillennial view of end times suggest there is only one final judgment for both believers and unbelievers. It occurs at the Second Coming of Christ at end of the Millennium. This is generally known as the Great White Throne Judgment mentioned in Rev 20:11.

-Those who hold a Premillennial view of end times suggest believers are judged and resurrected in their glorified bodies before the Millennium, not after. This occurs at the Rapture at the beginning of the 7-year Tribulation and/or the Second Coming of Christ at the end of the Tribulation. Then, the 1,000 year Millennium begins. 

Believers are judged for their deeds to determine the rewards or crowns they will receive in heaven (1 Cor 9:24-25). It's not a time to punish sin since Jesus took our punishment once and for all on the cross. Instead, believers will be judged for what they did for Jesus, whether good or worthless—wood, hay and straw (1 Cor 3:10-15). This judgment is generally known as the Judgement Seat of Christ (2 Cor 5:10). In the Greek, the word for “judgment seat” is bema. A bema was an elevated platform where victorious athletes received their crowns, similar to the medal stand in the Olympics.

Unbelievers are judged at the end of the Millennium in all three end-time views, Premil, Amil and Postmil. Unbelievers go to the Great White Throne Judgment where they are judged for their deeds to determine their degree of punishment in hell before being cast into the Lake of Fire. 

-However, with all the various end-time views Christians hold, the final result is the same: believers go to heaven with rewards, and unbelievers are cast into the Lake of Fire for eternal punishment.