In the AC cable there will be alternating current, in the DC cable there will be direct current. There’s no physical difference. Until you go into regulations, if it’s AC it’s probably at least a 100V, which means you need more shielding and other things compared to the cables running 12V in your car. read more
For DC, current distribution is uniform in all over cross section of cable so electrical cross-section = physical cross-section. For AC, current distribution is non uniform due to the time varying nature of magnetic flux produces. read more
Electrical current flows from a point of positive charge to a point of negative charge whilst essentially the electrons flow in the opposite direction. AC stands for an alternating current. read more