* Planets form from the leftover material after a star is born. Stars form from massive clouds of gas and dust. The Sun formed in this way, consuming most of the material in its vicinity. Planets form from the remaining dust and gas that didn't get pulled into the star.

* Stars and planets are fundamentally different. Stars are massive, hot balls of gas that produce energy through nuclear fusion. Planets are much smaller, cooler, and don't have the mass or internal pressure to sustain fusion.

* The Sun will eventually become a white dwarf. The Sun is a main sequence star, currently burning hydrogen into helium. In about 5 billion years, it will run out of hydrogen and expand into a red giant. Eventually, it will shed its outer layers, leaving behind a dense, hot white dwarf star.

In short, the Sun is a star, and planets form from the leftover material after a star is born. The Sun will never become a planet.