The world has three dimensions of space: length, width and depth and one dimension of time. Superstring Theory postulates the universe exists in ten different dimensions and M-theory 10-11 dimensions. Multiverse are multiple universes, with space, time, matter, energy, information, with their physical laws and constants. There are several universes: Level I: An extension of our universe. Level II: Universes with different physical constants. Level III: Many worlds interpretation of quantum mechanics (QM). Level IV: All universes are equal with different structures. Our universe is tuned for conscious life. Quantum field theory combines, special relativity and probabilistic QM. Max Planck's study of blackbody radiation started QM, atoms, absorb and emit quanta of electromagnetic radiation, as quantum harmonic oscillators. Light are photons . Electromagnetism is a field with electric potentials at every point in space. Light and matter are waves and particles. Fractals are equal at different magnifications. In string theory, particles are one dimensional strings with mass, charge, candidates for a theory of everything. Matter is described in QM as Branes through space.