In this chapter we will introduce the electric field \(\textbf{E}(\textbf{r})\) for a system of stationary point charges and calculate the total energy of the system. Furthermore, an asymptotic multipole expansion of the field will be analyzed for localized charge distributions and lead to characteristic properties of the systems, i.e. the total charge Q, the electric dipole moment \(\textbf{d}\) and the electric quadrupole tensor \(Q_{ij}\) .