What is the significance of ferromagnetism?

Ferromagnetism is the property of a material in which particles (called magnetic moments) arrange themselves parallel to each other in the presence of a magnetic field. These particles remain arranged even when the magnet is removed, with magnetism occurring at the atomic level and the field having a direct effect on the electrons in an atom. Electrons spinning in opposite directions can be in the same orbit of the atom and even change orbits, possessing a stronger repulsion. This allows electrons to arrange themselves in parallel and results in the parallel structure of ferromagnetic materials, such as iron and nickel. Temperature also has a strong influence on ferromagnetic materials.