* The Sun's Fuel: The Sun is powered by nuclear fusion, primarily converting hydrogen into helium. This process generates immense energy, but the Sun has a finite amount of hydrogen fuel.

* Red Giant Phase: When the Sun runs out of hydrogen fuel, it will start fusing helium into heavier elements, causing it to expand into a red giant. This expansion will engulf the inner planets, including Earth.

* Planetary Nebula: As the Sun continues to fuse heavier elements, it will eventually become unstable and shed its outer layers, forming a planetary nebula. This is a beautiful, colorful cloud of gas and dust.

* White Dwarf: The remaining core of the Sun will collapse under its own gravity, becoming a dense, hot, and slowly cooling white dwarf. This dense core will be about the size of the Earth, but incredibly massive.

Important Note: The process of the Sun becoming a white dwarf will take billions of years. Don't worry, it's a very long time away!