Here's why:

* Spectral Type: The Sun is classified as a G-type star, which refers to its temperature and spectral characteristics. G-type stars are known as yellow dwarfs.

* Size and Mass: The Sun is considered a medium-sized star, with a mass and size typical of yellow dwarfs.

* Lifetime: Yellow dwarfs have a lifespan of several billion years. Our Sun is roughly halfway through its life.

So, while there are many different types of stars in the universe, the Sun is categorized as a yellow dwarf.