Depending of their location, the lightning flashes and strikes are divided into direct and nearby ones. Every structure and every external service (incoming lines) may be influenced by direct and by nearby strikes.
Structures, due to a greater use of non inflammable materials, are increasingly resistant to direct lightning flashes. However, the equipment therein, due to an increase in the variety of the equipment and its electromagnetic sensitivity, is at risk to a greater extent from the effects of direct and nearby lightning flashes (the effects of entire and partial lightning currents and their electromagnetic fields).