What are stars and what are they made up of?

The celestial self-luminous object which produces energy on their own in the form of radiation due to thermonuclear fusion process is called Stars. The star seems to be permanent and of the same nature as if they don’t undergo any changes. They are of different colour the one which is red has the lowest surface temperature and the star of blue colour has the highest surface temperature.

They are made of various gases like hydrogen and helium. Star bigger in size compared to the sun have carbon-nitrogen thermonuclear fusion process in their cores.