What exactly does poential difference mean? Why does a current flow with voltage difference?
The first thing to note is that electrons flow from the negatively-charged to the positively-charged whereas we always talk of electricity as flowing from the positive to the negative. For direct current, as from a battery, there is a continuous flow of electrons in one direction (from the -ve to the +ve). A battery is simply a storage device for energy and the maker stuffed way too many electrons onto the -ve side and they want to flow to the +ve side and neutralize the charge imbalance. If you connect the terminals of the batteries to each other — as through a light — the electrons will flow and keep flowing until the charge has moved to equalize — and the battery is flat (or dead). With rechargeable batteries, you can use electrical power to put more electrons on the negative side and make the battery live again. If you think of a direct current circuit as being a hose attached at the top end to a tank of water and at the bottom to an empty container, you may understand the poten
