How many phases does the sun go through?

The sun primarily goes through three major phases in its life cycle: the main sequence, the red giant phase, and the final stages as a white dwarf. During the main sequence phase, which lasts about 10 billion years, the sun fuses hydrogen into helium. After exhausting its hydrogen fuel, it expands into a red giant, eventually shedding its outer layers. The remaining core then contracts into a white dwarf, which will cool and fade over billions of years.