Fisyon, or fission, is a nuclear reaction in which the nucleus of an atom splits into two or more smaller nuclei, along with the release of energy. This process typically occurs in heavy elements like uranium or plutonium. The energy released during fission can be harnessed for various applications, including generating electricity in nuclear power plants. In addition to energy production, fission is also a key process in the development of nuclear weapons. When a fission reaction occurs, it can trigger a chain reaction, leading to a rapid release of energy. This principle is fundamental to both peaceful and military uses of nuclear technology.