Before we move to Mihailescu's proof, let us cover some more mathematical concepts (so that we feel superior to the people around us, just kidding 😄),
There is an interesting theorem that Mihailescu uses in his proof, called the Stickelberger's theorem,
This is a result of algebraic number theory, which gives more information about Galois Module structure of class groups of Cyclotomic Fields. This theorem consists of Stickelberger's element and Stickelberger's ideal. I will now state the complete definition of the theorem and then visit its corners as we move along,