I think the difference between pig iron and wrought iron is mainly reflected in the carbon content, properties and uses.

Carbon content: the carbon content of pig iron is between 2% and 6.69%, and that of wrought iron is less than 0.04%.

Properties: wrought iron has soft texture, good ductility, easy deformation, low strength and hardness, and is suitable for forging and welding. Pure iron, as an electrical material, has high permeability and is used to make various iron cores. Pig iron contains more carbon, is wear-resistant and can be cast, but it is hard and brittle and is not suitable for forging. According to the different carbon content, pig iron can also be divided into steelmaking pig iron and casting pig iron.

Uses: wrought iron is mainly used as raw material for electrical materials and high-grade alloy steel, and rarely used as structural material. Pig iron is mainly used in casting field, such as making iron castings.