An equipotential surface is a three-dimensional surface on which the electric potential is the same at every point. This means that no work is required to move a charge anywhere along that surface because the electric potential does not change. Equipotential surfaces are always perpendicular to electric field lines, and they never intersect. For example, around a point charge, equipotential surfaces form concentric spheres; in a uniform electric field, they are parallel planes. The electric field direction is always normal (perpendicular) to these surfaces, which visually helps in understanding the behavior of electric fields and potentials.
