According to theory, that is the kind that should be generated by the nuclear fusion of hydrogen in the sun. (discovermagazine.com)
The total amount of energy that a star can generate through nuclear fusion of hydrogen is limited by the amount of hydrogen fuel that can be consumed at the core. (newworldencyclopedia.org)
This means that it generates its energy by nuclear fusion of hydrogen nuclei into helium and is in a state of hydrostatic balance — neither contracting nor expanding over time. (newworldencyclopedia.org)