Wrought iron is a type of iron alloy characterized by low carbon content and a fibrous, malleable structure, setting it apart from cast iron due to its superior ductility and resistance to thermal shock. Its formation historically involved purifying pig iron and repeatedly heating and working the metal through forging processes. This intensive thermal treatment drives out impurities, particularly slag, resulting in a material that is relatively pure iron with minute inclusions. Its inherent plasticity allows it to be shaped into complex forms and withstand significant mechanical stresses, making it valuable in structural applications prior to the widespread adoption of modern, high-grade steel alloys.