Electric and magnetic fields are coupled in dynamical (time dependent) situations. The fact, that a magnetic field, which changes in time, produces a time dependent electric field, which induces a magnetic field changing with time, is incorporated in Maxwell’s equations. These equations separate in a stationary situation, which is characterised by \(\displaystyle \frac {\partial \boldsymbol {B}(\boldsymbol {r},t)}{\partial t} = \boldsymbol {0} \qquad \mathrm {and} \qquad \frac {\partial \boldsymbol {E}(\boldsymbol {r},t)}{\partial t} = \boldsymbol {0} \;, \) into the set of differential equations for stationary fields, which have been discussed in the first chapters. The treatment of the Maxwell equations starts with the discussion of the experimental basis of electrodynamics, the law of induction (Chap. 1.1). One of the variants of this law corresponds to one of the four Maxwell equations, which will be assembled in Chap. 1.2, on the basis of the original argumentation of Maxwell. The physical content of these equations is presented in two sections. The homogeneous or free Maxwell equations describe the situation in domains of space without any sources as charges or currents changing with time. They are wave equations with solutions, which describe the propagation of electromagnetic waves (Chap. 1.3). The solution of the inhomogeneous or complete Maxwell equations deals with questions concerning the generation of electromagnetic waves by charges and currents changing with time, the topic of senders (transmitters). An introduction to this topic is discussed in Chap. 1.4, in the form of the energy and momentum aspects of electrodynamics: Electrodynamic fields transport energy and momentum. An economical formulation of the transmission problem calls for the introduction of time dependent electromagnetic potentials (Chap. 1.5), which are a way to access the solution of the inhomogeneous wave equation (Chap. 1.6). Applications of electrodynamics as optical problems, the mode of operation of transformers and others are found in Chap. 2 .