Why do Stars Explode??

A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion.Stellar explosion can refer to:

Nova
Kilonova
Micronova
supernova
Type Ia supernova
Type Ib and Ic supernovae
Type II supernova
Superluminous supernova
Pair-instability supernova
Hypernova
Supernova impostor, stellar explosions that appear similar to supernova, but do not destroy their progenitor stars
Failed supernova
Luminous red nova, an explosion thought to be caused by stellar collision
Solar flares are a minor type of stellar explosion
Tidal disruption event, the pulling apart of a star by tidal forces