As with all important scientific theories, quantum mechanics has advanced a great deal since its initial formulation and confirmation. The original quantum theory has advanced to the point today at which scientists have described what the standard models of subatomic particles in the universe are (fermions, bosons, quarks, leptons, and so forth) and their very complex behaviors and interactions (quantum electrodynamics, quantum chromodynamics, and more). The fundamental nature of matter and energy is still being studied today, and many more exciting discoveries and advances are sure to come in the future.