Each star is an enormous glowing ball of gas like our Sun. A star shines because secretes tremendous amount of power. This energy is formed by the so-called thermonuclear reactions.
Each star includes many chemical elements. For example, the Sun revealed the presence of at least 60 elements. Among them, hydrogen, helium, iron, calcium, magnesium and others.
Why do we see the Sun so small? Yes, because it is very far from us. Why do stars look tiny? Remember how small we think our huge Sun is but a soccer ball. This is because it is very far from us. And the stars are much, much more!
Stars in the likeness of our Sun illuminate the Universe around him, warm around them, planets and give life. Why do they glow only at night? No, they also Shine, just don't see them. In the daytime, our sun with its rays illuminates the blue planet's atmosphere, which space is hidden as if behind a curtain. At night the curtain opens and we see the magnificence of the cosmos — stars, galaxies, nebulae, comets and many other wonders of our Universe.