Conductor
Aluminum foil is a conductor. This is because it conducts electricity easily and has good conductivity. Aluminum is a good conductor, so aluminum foil made from aluminum also has good conductivity. Although aluminum foil also has some insulating properties, especially when the surface is covered with an oxide layer, it is mainly considered a conductor. In practical applications, such as when used on the surface of household electrical wires, aluminum foil can effectively isolate the influence of external current and avoid problems such as electrical leakage, which further proves that its conductivity rather than insulation is its main physical property. 12
In addition, the insulation of aluminum foil is usually not as significant as its conductivity, and its conductivity is more prominent when there is no oxide layer covering it. Therefore, it can be considered that aluminum foil is mainly a conductor, but it also has some insulating properties, especially under certain conditions such as surface oxidation.