A generalized approach to the study of the dynamic behavior of electrochemical systems is presented in terms of the transient impedance technique. It is shown that interpretation of the time domain electrode response to an arbitrary perturbation by conversion of both functions to the frequency domain allows maximum usage of experimental information with minimum ambiguity. Both real and imaginary axis Laplace transformation are used to generate Z(σ) and Z(jω), respectively. The theoretical and experimental usefulness of both functions is considered in detail and it is shown that a very wide frequency range extending to 108 rad/sec may be studied. The basis for the use of aperiodic equivalent circuits to represent active or passive electrodes is considered and sample circuits, rigorously derived, are presented. The equivalent circuit approach is thus generalized and it is shown how their use may constitute shorthand notation for the rigorous solution of the differential equations used to describe a particular electrode model. Application of the transient impedance method to potentiostatic techniques is presented with emphasis on the manner in which this approach allows instrumental errors and artifacts to be markedly reduced, particularly at high frequencies.