The Sun is a star, specifically a G-type main-sequence star (G dwarf) located at the center of our solar system. It is primarily composed of hydrogen and helium, undergoing nuclear fusion to produce energy. This process generates the light and heat that sustains life on Earth. The Sun is about 4.6 billion years old and contains more than 99% of the total mass of the solar system. Its immense gravitational pull keeps the planets, including Earth, in orbit around it. Understanding the Sun is crucial for many fields of science, including astronomy, climate science, and solar physics.