Here is my understanding: Voltage shows the potential difference between 2 points in a circuit and a higher voltage correlates with a higher electromotive force (emf) that moves the electrons through the wire. Voltage is measured in Joules/coulomb, so electrons moving in a circuit that has higher voltage have higher energy per coulomb. How do electrons express this higher energy? By moving with greater speed? By giving off more heat? By extension, how does a voltmeter measure voltage in a circuit?

Thanks for any insight.