Stellar flux refers to the total power emitted by a star, measured as the energy of radiation passing through a unit area per second. It is synonymous with radiative flux density and irradiance when considering surface area. This concept is crucial for calculating apparent magnitude, which compares the energy received from stars to a reference flux. Additionally, the term may lead to confusion with solar wind flux, as both involve energy measurements but pertain to different contexts. Understanding stellar flux is essential for grasping how starlight affects observations of celestial bodies.