The Sun is composed of several layers, each with distinct characteristics. The outermost layer is the photosphere, which emits visible light and is where sunspots can be observed. Below this lies the chromosphere, a thin layer that can be seen during solar eclipses, and the corona, the Sun's outer atmosphere, which extends millions of kilometers into space. The core is the Sun's innermost layer, where nuclear fusion occurs, producing energy that powers the entire solar system. Surrounding the core are the radiative zone and the convective zone, which help transport energy to the surface. Together, these layers create the complex structure of the Sun.