This book collects research and review articles covering some recent trends in nonrelativistic quantum electrodynamics, specifically the interaction of atoms or molecules within the quantum electromagnetic radiation field and the related physical effects. Specific topics covered are: two- and three-body dispersion interactions between atoms and molecules, both in the nonretarded van der Waals and the retarded Casimir–Polder regime; vacuum field fluctuations of the electromagnetic field and their effect in atomic systems; dispersion interactions between uniformly accelerating atoms and relation with the Fulling–Davies–Unruh effect; dynamics of atomic systems under strong electromagnetic fields; symmetries in quantum electrodynamics; and open quantum systems.