At the end of its evolution, a star can become one of the following:
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Black Hole - This can occur if the star is massive enough (typically more than about 20-25 times the mass of the Sun). After a supernova explosion, the core collapses under its own gravity, possibly resulting in a black hole.
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Neutron Star - For stars with a mass between about 8 and 20 times that of the Sun, a supernova will expel the outer layers, leaving behind a core that becomes extremely dense, compressing into a neutron star.
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White Dwarf - Stars with a mass less than about 8 times that of the Sun will shed their outer layers, forming a planetary nebula, while the core remains as a white dwarf, which gradually cools over time.
So, to summarize, at the end of their evolution, stars can become a black hole, a neutron star, or a white dwarf, depending on their initial mass.