Magnetic hysteresis refers to the lag between the magnetization of a material and the external magnetic field applied to it. When a magnetic field is applied, the material becomes magnetized, but when the field is removed, the material does not immediately return to its original state. This phenomenon is commonly observed in ferromagnetic materials, such as iron. The hysteresis effect is often represented graphically in a loop called the hysteresis loop. The area within this loop indicates energy loss due to the material's internal friction during magnetization and demagnetization. Understanding magnetic hysteresis is crucial in designing electromagnetic devices like transformers and magnetic storage media.