Ferromagnetism is a property exhibited by certain materials characterized by a strong and permanent magnetic moment. In these substances, individual atomic magnetic moments spontaneously align in the same direction, creating a macroscopic magnetic field. This alignment arises due to the exchange interaction between neighboring atoms and the parallel orientation of electron spins. Ferromagnetic materials, such as iron, cobalt, and nickel, display unique magnetic behaviors, such as spontaneous magnetization and the ability to retain strong magnetic fields. Below a critical temperature called the Curie temperature, ferromagnetic materials exhibit this behavior, making them valuable in applications like magnetic storage, transformers, and various electronic devices.