Question

Why do stars gives out heat and light

Answer 1

because they are made of hot gasses which makes them shine. when they die, they emit heat and light.....

Answer 2

using our sun as an example ,nuclear fusion in the core of the sun produces the heat where the temperature is roughly 15million K.
.......other stars exhibit a range of surface temperatures, spectral peaks and also have differing core temperatures. "
I hope it is helpful to you