There are two main types of magnitude:

* Apparent magnitude: This refers to how bright a star appears from Earth. It's a subjective measurement, affected by the star's distance from Earth and how much dust and gas are in the way.

* Absolute magnitude: This is a measure of a star's intrinsic brightness, as if it were observed from a standard distance of 10 parsecs. It's a more objective measurement, allowing astronomers to compare the true luminosities of stars.

It's important to note that the magnitude system is an inverse scale: brighter objects have *smaller* magnitudes. This means a star with a magnitude of -1 is brighter than a star with a magnitude of 1.