Metal ions of ferromagnetic substances are randomly oriented in normal condition and substances do not act as a magnet. But when metal ions are grouped together in small regions, called as domains, each domain acts as a tiny magnet and it produces a strong magnetic field. In such condition ferromagnetic substances act like a magnet. When the ordering of the domain in group persists even after removal of the magnetic field a ferromagnetic substance becomes a permanent magnet. While domains are grouped in parallel and anti – parallel direction but in unequal number in ferromagnetic compounds. Thus, ferromagnetic substances, such as Ni, Co, Fe would make better permanent magnets rather than ferromagnetic substances.