Ferromagnetic substances such as iron, cobalt, nickel, or ferrite are different. The electrons' spins inside them can spontaneously align within a small range to form a spontaneously magnetized region, and this spontaneously magnetized region is called a magnetic domain. After ferromagnetic substances are magnetized, the internal magnetic domains are neatly and uniformly arranged in the same direction, strengthening the magnetism and thus forming a magnet. The process of a magnet attracting iron is the process of magnetizing the iron block. The magnetized iron block and the magnet generate an attractive force between different polarities, and the iron block is firmly "stuck" to the magnet. We then say that the magnet has magnetism.
Most substances are composed of molecules, molecules are composed of atoms, and atoms are composed of a nucleus and electrons. Inside an atom, electrons are constantly spinning on their own axes and revolving around the nucleus. These two kinds of electron motions can generate magnetism. However, in most substances, the directions of electron motions are different and disorderly, and the magnetic effects cancel each other out. Therefore, most substances do not exhibit magnetism under normal conditions. The fact that magnets attract iron is determined by the characteristics of magnets. If it is explained in terms of atomic current, it is the magnetic field generated by the current that magnetizes other objects. The magnetized object generates an electric field, and the electric fields interact to produce a force.
