Here's a simplified breakdown:

* Protostar: The Sun started as a cloud of gas and dust that collapsed under gravity. This stage is very short compared to the others.

* Main Sequence: This is the longest stage, where the Sun fuses hydrogen into helium in its core, releasing energy as light and heat. The Sun is currently in this stage.

* Red Giant: When the Sun runs out of hydrogen fuel, it will expand and cool, becoming a red giant.

* Planetary Nebula: The outer layers of the Sun will be ejected, creating a beautiful shell of gas called a planetary nebula.

* White Dwarf: The remaining core of the Sun will be a dense, hot, and slowly cooling white dwarf.

The Sun is about halfway through its main sequence stage, which is expected to last for about 10 billion years.