How does voltage relate to electric potential difference?

yes, voltage is essentially the same thing as electrical potential difference. The only real difference is that voltage will ALWAYS have a polarity - it is a vector quantity. So saying this is 5 volts means nothing unless you say it is 5 volts from plate a to plate b. On the other hand, potential difference does not imply a direction and is more of a scaler value.

I am not sure what this is referring too

Oh I think i see.. the  statement Each battery terminal  and the plate of the capacitor it is connected to.. means

if i connect the plus voltage of the battery to the top plate  then the top plate becomes plus charge..

now if the other terminal of the battery is connect to the lower plate of the capacitor  now the other terminal must be negative so the  other side of the  capacitor must have a  negative charge now


if the battery is 12 volt car battery then the  voltage from  one terminal to the other is 12 volts

since these terminals are connected to the capacitor then the voltage is now 12 volts the top plate is positive with respect to the lower plate so  the potential difference between the plates is  12 volts..

it doesnt matter if  the  lower plate is positive  110 volts
and the upper plate is 122 volts positive..

then the potential difference will still be  12 volts..


I hope that helps  a bit the voltage is a measure of the potential difference  
a potential difference of 12 volts means the to  one electrode is 12 volts more than the other..

Voltage (Watts) is the difference in electric potential (Joules) between 2 points per unit charge (Coulombs).

I believe what's being implied is that the voltage *drop* across the capacitor is equal to the voltage provided by the battery.  In that case, Voltage is also equal to the total charge on the plates over the capcitance.

Voltage is potential (or pressure)

Potential difference is therefore voltage difference

You can have the same voltage in two different places connected together and current will not flow.

There has to be a potential (i.e pressure) difference to make current flow.

A voltage must be measured against something, must have a reference. We might say that a voltage exists with "respect to earth" meaning above zero.

But a potential difference exists between say 9 volts and 6 volts. The difference is 3 volts and current will flow if there is a connection.

By the way, this is confusing but electrons are negatively charged particles and therefore attracted to the positive. But in conventional electrics current flows from positive to negative  -we have to live with it.