Electrons and protons possess charge as a fundamental property, with charge being defined differently depending on the theoretical framework, such as quantum mechanics or classical electromagnetism. Charge is linked to the conserved quantity associated with U(1) gauge symmetry in quantum mechanics and can also be understood through experimental measurement procedures. The reason electrons and protons have charge is intrinsic to their definitions, with protons being composed of quarks, which inherently carry charge. While the question of why they have charge may seem complex, it is not meaningless; it reflects the nature of fundamental properties in physics. Ultimately, charge defines the energy difference between particles, similar to how properties of light can be explained.