Electric potential energy is the stored energy possessed by a charged particle or system of charged particles within an electric field due to their positions relative to each other. It represents the ability of charges to do work by virtue of their positions or configurations in an electric field. When charges are brought closer together, their electric potential energy increases as work is done against the electric force to move them closer. Conversely, separating charges decreases their potential energy, releasing energy into the electric field. Understanding electric potential energy is essential in explaining the behavior of charged particles, electric circuits, and systems of charges in various applications in physics and engineering, such as in capacitors, batteries, and electrical interactions in matter.