Here's the breakdown:

* Nuclear Fusion: The Sun's core is incredibly hot and dense, allowing hydrogen atoms to overcome their natural repulsion and fuse together.

* Hydrogen Fusion: Two hydrogen atoms (each with one proton) fuse to form a deuterium atom (one proton, one neutron) and a positron (an anti-electron).

* Helium Formation: The deuterium then fuses with another hydrogen atom, producing a helium-3 atom (two protons, one neutron). Two helium-3 atoms then fuse, producing a helium-4 atom (two protons, two neutrons) and two protons.

In essence, the Sun converts hydrogen into helium, releasing energy in the process. This energy is what powers the Sun and provides light and heat to Earth.