What does an electric dipole consist of?

An electric dipole consists of two point charges of equal magnitude but opposite sign (one positive, one negative) separated by a fixed, small distance. This simple configuration creates an electric field pattern that's distinctly different from that of a single charge—the field lines emerge from the positive charge and terminate at the negative charge, with the strongest field concentrated near the charges and weakening rapidly with distance. The dipole is characterized by its electric dipole moment, a vector pointing from the negative to the positive charge with magnitude equal to the charge multiplied by the separation distance.

In real-world chemistry and physics, perfect point charges don't exist, but many systems approximate electric dipoles effectively. Polar molecules like hydrogen chloride (HCl) behave as electric dipoles with partial charges rather than full elementary charges, while ion pairs in solution act as dipoles with complete charge separation. The dipole concept becomes particularly powerful when explaining macroscopic phenomena: it describes how molecules align in electric fields (the principle behind liquid crystal displays), how substances develop surface charges, and why certain materials exhibit ferroelectric properties. Electric dipoles also represent the first term in multipole expansion, a mathematical tool physicists use to describe complex charge distributions by breaking them into simpler components.