Hysteresis is a phenomenon where the state of a system depends not only on its current conditions but also on its past history. This is commonly observed in materials like ferromagnetic substances, where the magnetization of the material lags behind the applied magnetic field. When the field is removed, the material retains some magnetization, illustrating how past influences affect present behavior. In broader contexts, hysteresis can be seen in various systems, such as mechanical systems and thermodynamics. For example, in a rubber band, stretching it and then releasing it does not return it to its original shape immediately. This delay in response highlights the importance of historical states in determining current outcomes.