What is the setting of The Sword of Shannara by Terry Brooks?

The Sword of Shannara appears to take place on a version of Earth. The humans of old used to be extremely scientific and not believe in magic or other races, such as Dwarfs and Elves. Then there was a great war that ended in a holocaust that destroyed the landscape, most knowledge of science, and altered the location and physical appearance of the surviving humans and creatures.