Quantum Electrodynamics describes the interactions of light with matter as well as those of charged particles with each other.  The foundation of quantum electrodynamics was laid by P.A.M. Dirac when he discovered an equation describing the motion and spin of electrons that incorporated both Quantum Mechanics and the theory of special relativity.  The theory of quantum electrodynamics (which was tweaked and created in the late 1940s) rests on the idea that charged particles interact by emitting and absorbing photons.  The quantum electrodynamics theory has become a model for other quantum field theories.