Most matter is composed of molecules, which are made up of atoms, and atoms consist of atomic nuclei and electrons. Within an atom, electrons constantly spin and orbit around the atomic nucleus. Both of these movements generate magnetism. However, in most materials, the directions of electron movement are different and chaotic, causing their magnetic effects to cancel each other out. Therefore, most materials do not exhibit magnetism under normal circumstances.

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

After magnetization, ferromagnetic materials have their magnetic domains neatly arranged in a uniform direction, enhancing the magnetic properties, thereby forming a magnet. The process of a magnet attracting iron is the magnetization of the iron block, where the magnetized iron and the magnet's opposite poles generate an attractive force, causing the iron to stick firmly to the magnet. We then say that the magnet has magnetism.