A supernova is a powerful explosion that occurs when a star exhausts its fuel and can no longer maintain a balance between gravitational collapse and the fusion reactions in its core. Depending on the size and mass of the star, this explosion can either result in the complete destruction of the star or its transformation into a neutron star or black hole. Supernovae are important astronomical events that play a critical role in producing heavy elements that make up our universe, such as iron and gold. It is also used as a standard candle to measure astronomical distances. There are two main types of supernovae: Type I and Type II. Type I supernovae are believed to be caused by the explosion of a white dwarf star, while Type II supernovae are the result of the explosion of a massive star.