Here's why:

* The vast majority of stars are relatively small and low-mass. These stars, like our Sun, are classified as "main sequence" stars.

* Main sequence stars spend most of their lives fusing hydrogen into helium in their cores. This process generates the energy that makes them shine.

* Eventually, the hydrogen fuel runs out. The star then enters a phase of instability, expanding into a red giant.

* The core of the red giant continues to contract and heat up. Eventually, the core becomes hot enough to fuse helium into heavier elements like carbon and oxygen.

* For stars like our Sun, this process doesn't continue much further. The core eventually becomes a dense, hot ball of mostly carbon and oxygen, surrounded by a thin layer of hydrogen and helium.

* This dense core is a white dwarf. It's incredibly hot but slowly cools down over billions of years, eventually becoming a cold, dark object called a black dwarf.

While white dwarfs are the most common stellar end state, some massive stars eventually become neutron stars or black holes after going through supernova explosions. But these are much less common than white dwarfs.