Ferromagnetic materials get magnetic properties not only because their atoms owns a magnetic moment but also because the material consists of small regions called as magnetic domains. A magnetic domain is a region of the crystal in which all the spin magnetic moments are applied to a magnetic moment in one direction only. This alignment generates as the material creates its crystalline structure during solidification from the molten state. During solidification a million or more atom moments are aligned parallel so that the magnetic force within the domain is strong in one direction. Ferromagnetic materials obtain saturation magnetization in each of the domains without an external magnetic field being applied. Even though the domains are magnetically saturated the bulk material can not demonstrate any signs of magnetism as the domains develop themselves are randomly oriented relative to each other. Ferromagnetic materials turn out to be magnetized when the magnetic domains inside the material are aligned. This can be done by placing the material in the strong external magnetic field or by passing electrical current through the material. Some or the entire domain can become aligned. The more the domains are aligned, the stronger the magnetic field in the material. When the entire domain is aligned, the material said to be magnetically saturated. When a material is magnetically saturated then no extra amount of external magnetization force will make an increase in its internal level of magnetization.