Here's a breakdown of the process:

* Nuclear Fusion: The sun's energy comes from nuclear fusion. This is where atomic nuclei combine to form heavier nuclei, releasing tremendous amounts of energy in the process.

* Hydrogen Fusion: In the sun's core, hydrogen nuclei (protons) collide at extremely high temperatures and pressures. This causes them to fuse together, forming helium nuclei.

* Energy Release: The fusion process releases a tremendous amount of energy, mostly in the form of gamma rays. These gamma rays are then absorbed and re-emitted as light and heat, which is what we experience as sunlight.

So, the sun doesn't "burn" hydrogen in the traditional sense of combustion. Instead, it fuses hydrogen atoms to create helium, and that process is what fuels the sun's energy.