First Layer: The Sun's core is the central region where nuclear reactions consume hydrogen to form helium. These reactions release the energy that ultimately leaves the surface as visible light. ... In the second step a proton collides with the deuterium to produce a helium-3 nucleus and a gamma ray.
Second Layer: The Sun's radiative zone is the section of the solar interior between the innermost core and the outer convective zone. In the radiative zone, energy generated by nuclear fusion in the core moves outward as electromagnetic radiation. In other words, the energy is conveyed by photons.
Third Layer: The convection zone is the outer-most layer of the interior. It extends from a depth of 200,000 km up to the visible surface of the Sun. Energy is transported by convection in this region. The surface of the convection zone is where light (photons) is created.