Just like in Junior cert energy, potential is that which draws ...............
Pd and voltage are almost the same thing; they are both measured in volts.
A voltage when applied to a circuit is called an emf.
Sources of emf: mains, simple cells, lead-acid accumulator, car batteries, dry batteries, thermocouple.
Potential difference is like a height difference between the current will only flow if there is such a difference in potential
The unit of potential is the Volt, named after Alessandro Volta wiki,
the 1st cinema in Dublin 1904 founded by James Joyce was called the Volta.