Simple explanation of string theory, please don’t plagiarize.

String theory turns the page on the standard description of the universe by replacing all matter and force particles with just one element: Tiny vibrating strings that twist and turn in complicated ways that, from our perspective, look like particles

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String theory tries to model the four known fundamental interactions—gravitation, electromagnetism, strong nuclear force, weak nuclear force—together in one theory. This tries to resolve the alleged conflict between classical physics and quantum physics by elementary units—the one classical force: gravity, and a new quantum field theory of the other three fundamental forces