What does the Extragalactic Background Radiation, from gamma-rays through to radio waves, tell us about the formation and evolution of structure in the universe? A workshop at the Space Telescope Science Institute was dedicated to address just this question: it provided a unique opportunity for observational astronomers and theorists to share their expertise and to help synthesise a new understanding. Fourteen invited reviews from internationally renowned experts are presented here as an edited and coherent overview. Chapters are dedicated to the gamma-ray, X-ray, ultraviolet, optical, infrared, microwave and radio backgrounds as well as to the detection of anisotropies and the theory of structure formation. Together these reviews provide a unique, multi-wavelength overview of the Extragalactic Background Radiation and how it relates to structure in the universe. They summarise our present knowledge, highlight outstanding problems and provide focus for future work. In this way they provide a unique reference for graduates and professionals in astronomy, cosmology and physics.