How is luminosity related to size?

Luminosity is the total amount of energy emitted by a star per unit time and is closely related to its size. Generally, larger stars have greater surface areas, allowing them to emit more light and energy, resulting in higher luminosity. This relationship is often described by the Stefan-Boltzmann law, which states that luminosity increases with the fourth power of the star's radius and temperature. Thus, a star's size and temperature significantly influence its overall brightness.