Magnet classification
Magnet: Generally defined as an object that can attract iron, cobalt, nickel and other substances.
Magnets are generally divided into permanent magnets and soft magnets.
Permanent magnet: that is, a magnet that can maintain its magnetism for a long time. The permanent magnet is a hard magnet, which is not easy to lose magnetism and is not easily magnetized.
Soft magnets: Most of the materials used as magnetizers and electromagnets, the polarity of soft magnets changes with the polarity of the applied magnetic field.