is potential difference required for current flow in a wire? How do you create the same? Relate it with the work done and charge.

Potential difference is created by giving one end of a conductor more potential than the other.

 

Potential is basically a quantity, which represents the amount of work a charge need to come from infinity to that point.

Actually the interations of that particle at that point, gives it energy enough to move, and potential is the quantity which denotes the ability of a particle to dissapate energy.