I noticed a couple of similar threads, but I thought it might be better to start a new one for clarity. Imagine a simple DC circuit with a static (time invariant) source of potential and a closed circuit with a simple conductor. If you were to trace the potential from the negative terminal to the positive terminal you would expect a linear gradient in potential between the two terminals. Now, take any point on the conductor. What determines the potential at this point? In electrostatics, electric potential at a point in space is determined by the grouping of static charges and distance from those static charges. What determines the potential inside a conductor? Do the electrons rearrange themselves within the conductor (e.g. bunching up closest to the negative terminal)? Does this occur at the speed of light?