The sun's core is where Hydrogen atoms produce energy as they convert to molecules of Helium. Helium that is produced by the conversion of hydrogen into energy is related to the solar core in the sense that the conversion process produces energy captured in the core. I hope this helps you.
Answer : The phenomenon called as Nuclear Fusion is observed in the sun's core or solar core, where 4 atoms of Hydrogen molecule combines to give two atoms of Helium. It is due to fusing of two Hydrogen atoms to form one Helium molecule. In the core of sun this fusion process occurs, changing of mass of Hydrogen atom into Helium releases lot of energy in the form of heat and light.
The reaction that occurs inside the solar core is given below;
