The differential in potentials at two points in an electric field is called as potential difference between two points. It is measure in Volts i.e. VAB is called the potential difference between points A & B. If the VAB is positive then it illustrates that the potential at point A is high compared to potential at point B. In this case there will be chance of movement of charged particle from A to B against to electrical field between the points.
VAB = VA – VB