In astronomy, the Sun is classified as a G-type main-sequence star. However, in astrology, it's grouped with the "planets" for convenience, even though it's technically the center of our solar system.
The Sun contains 99.86% of the mass in our solar system. Everything else - all the planets, moons, asteroids, and comets - makes up just 0.14%.
Astrologically, the Sun's central position mirrors its role as the core of your identity. Your Sun sign represents your essential self, purpose, and vital life force.