The star is a ball of hot gases
containing different kinds of elements at different cores. It has a very high
temperature that radiates all throughout the galaxy. The star has four
main parts; the core, photosphere, chromospheres and corona. The outer core of
a star located at the chromospheres contains mostly of hydrogen. Inside the hydrogen
is helium then carbon, oxygen, neon, magnesium silicon and the inert gas. When a
star releases energy it is due to the thermonuclear fusion of hydrogen into
helium. So the answer is fusion.
