This lecture covers the electromagnetic (EM) field in the context of Quantum Field Theory II, discussing topics such as gauge transformations, symmetry principles, and the quantization of the EM field. The instructor explains the coupling of the EM field to other fields, the concept of Noether currents, and the process of fixing the gauge. The lecture also delves into the Lorentz and temporal gauge fixing options, as well as the implications of Gauss's law. Throughout the lecture, the instructor emphasizes the importance of understanding the field redundancy and the Hamiltonian description in the context of Quantum Field Theory.