what do volts measure

Volts measure the electrical potential difference or electromotive force. Voltage is a measurement of the electric potential or "pressure" at which electricity flows through a system. It is the unit of electric potential difference, or the size of the force that sends the electrons through a circuit. When the electrons move between two points through a conductive material, they generate electric current. Electrons cant resist this trip, just like when you drop a ball on a slope. The law of gravity forcing the ball (electrons) to roll is the voltage or electrical voltage. A potential of one volt appears across a resistance of one ohm when a current of one ampere flows through that resistance.