Fundamental constituents refer to the basic building blocks of matter that cannot be broken down into simpler substances. In the realm of physics, these include particles such as quarks and leptons, which combine to form protons, neutrons, and electrons. These particles are essential for the structure of atoms, which make up all matter in the universe. In addition to particles, fundamental constituents also encompass the forces that govern their interactions. The four fundamental forces—gravity, electromagnetism, strong nuclear force, and weak nuclear force—play a crucial role in shaping the behavior of these particles and the formation of complex structures, including stars, planets, and living organisms.