A White Dwarf is a small, dense star that represents the final evolutionary state of stars like our Sun. After exhausting their nuclear fuel, these stars shed their outer layers, leaving behind a hot core that gradually cools over time. White dwarfs are typically about the size of Earth but contain a mass comparable to that of the Sun.
These stellar remnants are composed mostly of carbon and oxygen and are supported against gravitational collapse by electron degeneracy pressure. Over billions of years, a white dwarf will cool and fade, eventually becoming a cold, dark object known as a black dwarf, although none are believed to exist yet in the universe.