The purpose of the paper is to use fundamental theoretical and experimental elements of electrodynamics for deriving properties of radiation fields and of bound fields. A wide variety of examples prove that radiation fields and bound fields do not represent the same physical object. This conclusion is new. Some examples belong to the classical domain and others belong to the quantum domain. Consequences of this outcome affect several physical issues. In particular, these fields should be treated separately. For this reason, changes must be introduced to the present form of the fields’ Lagrangian density of quantum electrodynamics, where the fields tensor F^uvis a sum of bound and radiation fields. Since the Lagrangian density is a key element of the theory, its revision may entail changes of other specific issues. The recent failure of quantum electrodynamics to explain the electron and the muon data of the proton charge radius supports this conclusion.