electric wire as as Conductor of electricity

electric wire usually we look at every palce that is electric pool electric wire also as conductor delivery energy,when the energy conductor make it from some materials the materials is:copper,steel and iron cabel at the high voltage electric network having sid self and must different size and as delivered elctrical energy ,electric wire usually put in the electric pool ,and every wire having self voltage.and every cable have what size selfing. really the cable wire usually have different sizes every cable having different sizes because adjusted measure voltage and each of its constraints(ohm)