Gamma decay is a type of radioactive decay where an unstable atomic nucleus releases energy in the form of gamma rays. These rays are high-energy electromagnetic radiation, similar to X-rays but with even higher energy. Unlike alpha or beta decay, gamma decay does not change the number of protons or neutrons in the nucleus; it simply allows the nucleus to move from a higher energy state to a lower energy state. During gamma decay, the emitted gamma rays carry away excess energy, helping the nucleus achieve stability. This process often occurs after other types of decay, as the nucleus may still be in an excited state. Gamma decay is important in various fields, including nuclear medicine and radiation therapy, where gamma rays are used for imaging and treatment.