Question

How is a potential difference created between two points?

Answer 1

To create and sustain a potential difference you need something to move charges. That is, towards the point of higher potential. You just need a force larger than the repelling force, a battery is a clear example. Inside the battery, a chemical process creates such a force which pushes the electrons back up to the higher potential point (the negative pole/terminal of the battery). From this point, they again want to move back to the lower potential. They do this by running the circuit. When the electrons reach the lower potential, which is the positive pole/terminal of the battery, they are moved back again on the higher potential ready to travel once more.