What's the difference between soft magnet and hard magnet?

Magnetic materials can be roughly divided into hard magnetic materials and soft magnetic materials. Hard magnetic materials, that is, what we call permanent magnetic materials, refer to ferromagnetic materials with large hysteresis loops, high remanence, low permeability, high magnetoresistance and high coercivity. Hard magnetic materials are relatively difficult to magnetize and demagnetize, such as ferrite and NdFeB magnetic steel.

Soft magnetic materials have narrow hysteresis loops, high permeability and low remanence, and low coercivity and magnetic resistance. Such magnetic materials are easy to be magnetized and demagnetized, such as iron nickel alloy, cast steel, silicon steel sheet, etc. soft materials have high permeability, easy to be magnetized and demagnetized, small area surrounded by hysteresis loops, and relatively small hysteresis loss, Most of them are used in the iron core of motor.