1. Apparent Magnitude: This describes how bright a star appears to us on Earth. It's a subjective measurement, influenced by factors like distance and the amount of dust and gas between us and the star. A lower apparent magnitude indicates a brighter star.

2. Absolute Magnitude: This describes how bright a star *actually* is, regardless of its distance from us. It's an objective measurement that tells us the star's intrinsic luminosity. Absolute magnitude is defined as the apparent magnitude a star would have if it were located 10 parsecs (32.6 light-years) away.