The human eye can see about 6,000 stars in the night sky. Photographs reveal millions more in every direction. All of these stars reside in our Milky Way galaxy. But they are just a tiny fraction of the several hundred billion stars in our galaxy alone. Counting all the stars in all the galaxies, there are perhaps a hundred billion billion stars in the observable universe.
The stars in the sky seem permanent and unchanging because it takes millions of billions of years for their lives to unfold.
A supernova is the explosion of an entire star.
Our Sun is an ordinary star, just one among hundreds of billions of stars in the Milky Way Galaxy.