Phenomenon exhibited by materials like iron (nickel or cobalt) that become magnetized in a magnetic field and retain this magnetism when the field is removed. Ferromagnetism is one of the strongest forms of magnetism. It is responsible for most of the magnetic behavior encountered in everyday life and, along with ferrimagnetism, is the basis for all permanent magnets (as well as the metals that are noticeably attracted to them).

Some or all content above used with permission from J. H. Wittke.