Photons and Atoms: Introduction to Quantum Electrodynamics provides the necessary background to understand the various physical processes associated with photon-atom interactions. It starts with elementary quantum theory and classical electrodynamics and progresses to more advanced approaches. A critical comparison is made between these different, although equivalent, formulations of quantum electrodynamics.Using this format, the reader is offered a gradual, yet flexible introduction to quantum electrodynamics, avoiding formal discussions and excessive shortcuts. Complementing each chapter are numerous examples and exercises that can be used independently from the rest of the book to extend each chapter in many disciplines depending on the interests and needs of the reader.