Dispensational Premillennialism: see Premillennialism and Millennialism. The main distinction is that Dispensational Premillennialism teaches that the second coming occurs before the tribulation (following the rapture); whereas Classical Premillennialism teaches it occurs after the tribulation (with the rapture following the tribulation). They also believe that the Church and Israel are distinct entities, with Israel having a special place of prominence. Like both Millennialism and Premillenialism, this teaching denies that Death and the Devil have already been vanquished in Christ's death and resurrection.
Millennialism is also known as Chiliasm. This is a specific form of Millenarianism, with close ties to Premillennialism (like Classical Premillennialism, Millennialism is a post-tribulation belief where the second coming occurs after the tribulation, whereas Dispensational Premillennialism teaches that the second coming occurs before the tribulation). This belief claims that there will be a Golden Age in which Christ reigns for one thousand years on earth prior to the Final Judgment and the New Heavens and New Earth appear. This is not the end of the world, but rather a penultimate age prior to the end of the world. Some believe that before the Final Judgment there will be a final great battle with Satan and his army of demons. This teaching clearly denies that Christ has already conquered Death and the Devil; that His work is as of yet unfinished with Satan (the orthodox teaching would be that while Satan can still tempt us because of Original Sin, he no longer holds power over us through death because of Christ’s fully atoning work).
Premillennialism is an eschatological heresy predominant in protestantism. It is the belief that Jesus will return and physically reign over a literal one thousand year kingdom just before or just after His Second Coming. Premillennialists also believe in a rapture of believers and seven-year tribulation period (Dispensational Premillennialism believes the rapture and tribulation will happen before the thousand years kingdom in that order, Classical or Historic Premillennialism believes the rapture will happen after the tribulation, which occurs after the thousand year’s kingdom but before the second coming). They hold that the Church and Israel are the same entity (Dual Covenant Theology).
Postmillennialism is an eschatological heresy which teaches that Christ’s second coming will occur after the Millennium (some hold this to be a literal one thousand years, others that it is symbolic of a long period of time), a Golden Age of prosperous Christian ethics. It is in contrast to Premillennialism and the orthodox doctrine of Amillennialism—both of which are well established in various Christian denominations. Postmillennialism is considered rare compared to the other two. They also teach that Satan will gradually be defeated by expansion of the Kingdom of God before the second coming (like Millennialism, this denies that Christ has already completed His work on the Cross and already vanquished Death and the Devil). Many Postmillennialists are also followers of Preterism. Calvin defended both Premillennialism and Postmillennialism in different works.