"The Elements shall Melt" What does this mean?

As you hear a lot of talk about armageddon and the end of the world you will also here those who say the earth and heavens will be destroyed literally and then rebuilt. phrases such as "new heaven,new earth", 'the stars shall fall from heaven to the earth" and then this one where Peter in his letter to the church says "the elements shall melt with fervent heat". What do these things actually mean? Let's find out together.