QCD (Quantum Chromodynamics)

Quantum Chromodynamics (QCD) is a fundamental theory in particle physics that describes the strong interaction, one of the four fundamental forces of nature. It explains how quarks and gluons—the building blocks of protons and neutrons—interact through "color" charge, a property analogous to electric charge but specific to the strong force. QCD shows how quarks are held together within protons and neutrons by gluons, which act like exchange particles. This interaction is crucial for understanding the structure of matter in the universe, as it governs the behavior of the strongest forces binding atomic nuclei together.