What type of magnet retains its magnetism over time?

A permanent magnet is designed to retain its magnetism over time without the need for an external power source or additional energy. This property arises from the material's internal structure, which allows it to maintain aligned magnetic domains even after being magnetized. The most common materials used for permanent magnets include iron, nickel, cobalt, and various alloys, which have been treated in such a way that their magnetic poling remains stable.

In contrast, temporary magnets lose their magnetism once the external magnetic field is removed, as their magnetic domains are not permanently aligned. Artificial magnets can refer to a broad range of magnets created through human activity, but without the characteristic of long-lasting magnetism inherent in permanent magnets. Electromagnets, while capable of producing strong magnetic fields, only exhibit magnetism when an electric current is applied. When the current ceases, the magnetic effect dissipates, distinguishing them from permanent magnets.