Why do magnets have north and south poles?

A magnet’s north and south poles come from the alignment of tiny magnetic moments in its atoms. In ordinary permanent magnets, many electrons’ spins and motions line up in the same direction, producing a net magnetic field. That field behaves like a dipole, with two opposite ends that attract or repel other magnets depending on orientation. If a magnet is cut in half, each piece becomes a smaller magnet with its own north and south poles. This is why isolated magnetic poles have never been observed in nature.