In this artist's impression, the structures of a solar-like star and a red giant are compared. The solar-like star's interior is divided into three distinct zones: The uppermost is the Convective Zone, where energy is transported upward by streams of gas. The Radiative Zone extends to the core; here, energy is transported outward by radiation. The core occupies the central region, where energy is produced by fusion processes. In red giants, the Convection Zone is much larger, encompassing more than 35 times more mass than in the Sun.