The Standard Model

Physicists have developed a theory called The Standard Model that explains what the world is and what holds it together. It is a simple and comprehensive theory that explains all the hundreds of particles and complex interactions with only: 6 quarks; 6 leptons (the best-known lepton is the electron); and force carrier particles, like the photon. All the known matter particles are composites of quarks and leptons, and they interact by exchanging force carrier particles.