What term describes the brightness of a star compared to the Sun?

The term that accurately describes the brightness of a star compared to the Sun is luminosity. Luminosity is a measure of the total amount of energy emitted by a star per unit time, and it specifically refers to an intrinsic property of the star. When we refer to luminosity in the context of a star like the Sun, we often use it as a reference point, indicating how many times more or less luminous another star is than the Sun.

In contrast, magnitude typically relates to the apparent brightness of a star as seen from Earth, which can be influenced by distance and interstellar material. Apparent magnitude is specifically the brightness of a star from an observer's point of view, while absolute magnitude refers to the brightness a star would have if it were located at a standard distance from the observer (usually 10 parsecs). Thus, each of these terms describes different aspects of stellar brightness, but luminosity is the term that encompasses the total energy output compared directly to the Sun.