1. Basics of electrodynamics

In this paragraph, a brief historical review describes the development of the ideas that led Maxwell to unify the various experimental discoveries of the time with his famous equations. The local form of these equations, from which we derive differential equations such as the wave equations, involve scalar and vector operators linking the electromagnetic field and its sources at the point of observation and at a given time. To solve these equations, the number of unknowns must be reduced by introducing the effect of matter through constitutive relations.