The capacity for doing work that arises from position or configuration is called potential energy. An object may have electric potential energy by virtue of two key elements: its own electric charge and its relative position to other electrically charged objects. Moving an electric charge in a electric field requires or release energy. Such energy is called electric potential energy.
When a free positive charge q is accelerated by an electric field, such as shown in Figure it is given kinetic energy. The process is analogous to an object being accelerated by a gravitational field. It is as if the charge is going down an electrical hill where its electric potential energy is converted to kinetic energy. Let us explore the work done on a charge q by the electric field in this process, so that we may develop a definition of electric potential energy.