Most matter is composed of molecules, which are made up of atoms, and atoms consist of atomic nuclei and electrons. Inside an atom, electrons rotate and orbit around the atomic nucleus. Both of these movements produce magnetism. However, in most substances, the directions of the electron movements are varied and disorganized, with their magnetic effects canceling each other out. Therefore, most materials do not exhibit magnetism under normal conditions.

Iron, cobalt, nickel, or ferrite and other ferromagnetic materials differ; the electrons within them can spontaneously align within a small range, forming a spontaneously magnetized area, which is known as a magnetic domain.

After magnetization, ferromagnetic materials have their magnetic domains neatly aligned in the same direction, enhancing the magnetic property, thus forming a magnet. The process of a magnet attracting iron is the magnetization of the iron block. The magnetized iron block and the magnet attract each other due to opposite poles, and the iron block sticks firmly to the magnet. We say that the magnet has magnetism.