Do you know why the stars dies?

The life and death of stars.
The most obvious part of the Galaxy is stars. Stars contribute to the dynamics of the Galaxy in a way that is interwoven with the gas and dust.
Death of Stars
Sooner or later, stars run out of hydrogen in their cores.

For very heavy stars, it's sooner.
For very light stars, it's later.
After using up the helium in its core, a star burns helium in its core to make carbon. What happens after this depends on the mass of the star.
The result should be that the galaxy has been building up its supply of heavy elements.
In a low mass star in its last stage, with a helium burning shell and a carbon core, stellar modelling suggests that the helium burning shell becomes unstable, and burns in bursts. This causes the star to eject much of its outer layers.
The result is a ``planetary nebula'' which may last for 50,000 years before it dissapates into space.
In the case of heavier stars, the star makes heavier elements, up to iron, as we have seen.
Note that -
the Earth is made of heavy elements, iron, silicon, oxygen,...;
you are made mostly of carbon, oxygen and hydrogen;
so presumably the Earth and we are made of stuff that was manufactured in the middle of a star.