Particle physics is the study of the fundamental particles of the universe, or, in other words, particle physics is the study of really, really small stuff. Modern particle physics research is focused on subatomic particles, which have less structure than atoms. These include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), particles produced by radiative and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles. The particles that are dealt with in this field are governed by quantum mechanics. This signifies that they may show both wave-like and particle qualities. The overarching goal of particle physics is to identify the simplest objects of which matter is composed of, and to understand the integral forces that drive their interactions and combinations.