Electrodynamics provided the basis for the technological developments of our age. The first generators and electric motors were already developed in the nineteenth century. Telegraphy (with the construction of senders and receivers at an ever higher standard) followed. Optical questions, as the complete understanding of diffraction phenomena could be approached on a quantitative level. The examination of the radiation of moving point charges lead to the discovery of X-rays and the construction of particle accelerators (starting with bevatrons up to high energy machines), which opened a general field of research. A few examples of the many facets of practical electrodynamics will be introduced in this chapter. The CGS-system of units will be used throughout.