Electricity, insofar as delivering it through a medium is concerned, can be described by Ohm’s Law, which states that the voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions and temperatures remain constant.
V = IR | I = V/R | R = V/I
So, Voltage equals the Amperage (I) multiplied by the Resistance/Impedance (R). Hence, Amperage (I) equals the Voltage (V) divided by the conductor’s Resistance/Impedance (R), and Resistance/Impedance (R) equals the Voltage (V) divided by the Amperage (I).
Personally, however, I think the anime girls – waifu’s – provide a better and more easily remembered explanation. 😛