Nuclear physics is the branch of physics that studies the components and behavior of atomic nuclei. It explores the forces that hold the nucleus together, the interactions between protons and neutrons, and the processes of nuclear reactions, such as fission and fusion. This field helps us understand the fundamental building blocks of matter and the energy released in nuclear processes. Applications of nuclear physics are widespread, including in medicine, where techniques like radiation therapy are used to treat cancer. It also plays a crucial role in energy production through nuclear power plants, which harness the energy from nuclear fission to generate electricity.