The great explosion
Stars can die in many different ways, so it would be easier to explain it visually.
So when a star explodes, it usually explodes as a Planetary Nebula (which is the smallest variation) or a Supernova. But sometimes, if a star is especially big then it will end up as a Hypernova. That is just like a Supernova except it has a massive gamma ray explosion with more energy. After a Planetary Nebula the star turns into a white dwarf. After a Supernova it turns into a Neutron Star or a Black Hole. Black Holes suck up everything around them- even light! Once a local star to the Earth exploded in a Supernova, and it caused a gamma ray explosion, causing the Ordovician-Silurian extinction. It killed over 60% of all sea animals- only the second biggest extinction ever in history.