Common copper magnet wire is a copper wire with a thinner enamel insulation, rather than the usual thicker plastic.
You can use ordinary copper wire with plastic insulation, but the winding has the most turns. It will work, but it is not efficient.
The conductivity of the two wires is the same, but the electromagnetic copper wire is specially coated with a thin and high heat-absorbing material. Thin insulating material helps to form more turns in a short range (in motors, transformers, relays, etc.) and can absorb heat. Ordinary copper round enameled wire is insulated with thicker materials and may require more area to wind more turns. Therefore, the winding will not work effectively and the insulation may melt.
