A supernova is a powerful explosion that occurs at the end of a star's life cycle. This event can happen in two main ways: when a massive star exhausts its nuclear fuel and collapses under its own gravity, or when a white dwarf star accumulates enough material from a companion star to trigger a runaway nuclear reaction. Supernovas are incredibly bright and can outshine entire galaxies for a short period. The explosion disperses the star's outer layers into space, enriching the surrounding environment with heavy elements. These elements, such as carbon, oxygen, and iron, are essential for the formation of new stars, planets, and even life. Supernovas also play a crucial role in the evolution of galaxies, influencing their structure and composition.