According to dispensationalism, who is 'the dragon' and what are the differences between 'the dragon' and 'the beast'? Based in the question: According to full preterism, who is 'the dragon' and what are the differences between 'the dragon' and 'the beast'?

In some passages from the Bible there exists sentences such as: Revelation 12:9


  The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him.


and Revelation 13:4


  People worshiped the dragon because he had given authority to the beast, and they also worshiped the beast and asked, “Who is like the beast? Who can wage war against it?"


Since I am assuming that 'Satan', 'the beast', etc are the same entity then


  Who is 'the dragon' and what are the differences between 'the dragon' and 'the beast'?
I have been a classical Dispensationalist for forty-eight years, so I am quite familiar with the answer to this question. Most Dispensationalists believe that "the Dragon" is Satan, and "the Beast" is the Antichrist and his government. He is a man possessed by Satan who will be given a brief period to rule the entire world. According to Dana &amp; Mantey's A Manual Grammar of the Greek New Testament the prefix "anti" can mean "instead of" as well as "against", so this may lend support to the idea that the Antichrist is a counterfeit of Christ. The usage of the term "the Beast" in the question refers to "the Beast from the Sea" of Revelation 13:1-10.  There is another Beast from the Earth (Revelation 13:11-18) identified by Dispensationalists as the False Prophet (Revelation 16:13), a man who will lead the world to worship the first Beast from the Sea as god. Some Dispensationalists hold that the False Prophet is the Antichrist, but since "Christ" is actually a political term meaning "King" (Luke 23:2), most believe the first Beast is the Antichrist. Thus there is a kind of unholy trinity: the Dragon (anti-God the Father), the Beast from the Sea (anti-Christ the Son), and the Beast from the Earth (anti-Holy Spirit).

There are a large number of Dispensationalist writings on these issues, and I recommend a couple of good places to start that are a bit old, but still very relevant: Jesus is Coming by W.E.B. (William E. Blackstone)[1898; third edition 1932], and Things to Come: A Study in Biblical Eschatology (1958) by J. Dwight Pentecost.