Most substances are composed of molecules, which are made up of atoms, and atoms consist of atomic nuclei and electrons. Inside an atom, electrons rotate continuously and orbit around the atomic nucleus. Both of these movements generate magnetism. However, in most substances, the directions of electron movements are different and chaotic, leading to the cancellation of magnetic effects. Therefore, most substances do not exhibit magnetism under normal conditions.

Iron, cobalt, nickel, or ferrites, and other ferromagnetic materials differ in that their internal electron spins can spontaneously align within a small range, forming a spontaneously magnetized region known as a magnetic domain.

After magnetization, ferromagnetic materials have their magnetic domains neatly aligned in a uniform direction, strengthening their magnetism, thereby forming a magnet. The process of a magnet attracting iron is the same as the process of magnetizing the iron. Magnetized iron and a magnet with opposite poles attract each other, causing the iron to firmly stick to the magnet. We say the magnet has magnetism.