The core of most stars is made up mostly of hydrogen, with some helium and very small amounts of other elements, all held together due to the force of gravity.
Over time, the atoms of hydrogen and other elements react to each other by fusing, a process known as thermonuclear fusion. Enormous amounts of energy is released during this process. The energy is given off as light energy (the reason why we can see stars) and as heat (the reason why stars are said to burn).
As a star's core hydrogen is used up, the star appears to change colors due to the changing composition of elements being fused and the temperature being created by the reactions.
Stars lack oxygen, so you are correct, they don't "burn" in the sense that we think of this definition.
The Sun goes through nuclear fusion which is the result of combining hydrogen and helium from the Sun's core. This produces energy that is radiated from the core.
Stars produce energy by nuclear reaction. Nuclear fusion of hydrogen and helium helps the star to produce energy.
Hello! A star gets its energy from the nuclear fuel which is obtained by the nuclear rections that happen in the body of the star. The nuclear fusion happens when hydrogen and helium from the star's core combines together. So, this is how the light is formed from the sun.