In this study, the Sun is examined as the closest star to Earth and the primary source of energy. The aim of the research is to understand the internal structure of the Sun and the processes of energy production and transfer within it. The importance of this study lies in achieving a better understanding of the physical processes that influence the stability of life on Earth. The research method is based on theoretical analysis and the use of standard astrophysical models. The findings show that the Sun’s structure consists of three main regions: the core, the radiative zone, and the convective zone. In the core, energy is produced through nuclear fusion, mainly via the proton–proton cycle or the carbon–nitrogen–oxygen cycle. This energy is then transferred to the surface through radiation and convection, and is ultimately emitted into space in the form of electromagnetic waves.