Voltage

Similar term(s): potential, electromotive force, potential difference.

The difference in electrical charge between two points in a circuit expressed in volts which makes electrical charges flow through a closed circuit.

Source: GreenFacts

One can compare this potential difference to water pressure. As there can exist a pressure (difference in level for example) without an inevitable water circulation, one can detect the electric potential without an inevitable circulation of electrons : thus the terminal voltage of a plug is present if the light is switched on or switched off.

Alternating current & Direct current - Charge - Electric current

Static Fields

Fluorinated gases