Temporary magnetism occurs when certain materials, like iron or nickel, become magnetized in the presence of a magnetic field. This magnetization happens because the magnetic domains within the material align with the external field, allowing the material to exhibit magnetic properties. However, once the external magnetic field is removed, the domains return to their original random orientation, and the material loses its magnetism. This type of magnetism is different from permanent magnetism, where materials, such as neodymium, retain their magnetic properties even after the external field is removed. Temporary magnets are often used in applications like electromagnets, which can be turned on and off, making them useful in various devices, including motors and transformers.