Book excerpt: This NATO Advanced Study Institute provided an up dated understanding, from a fundamental and deep point of view, of the progress and current problems in the early universe, cosmic microwave background radiation, large scale structure, dark matter problem, and the interplay between them. The focus was placed on the Cosmic Microwave Background Radiation. Emphasis was given to the mutual impact of fundamental physics and cosmology, both at theoretical and experimental-or observational-levels, within a deep and well defined programme, and a global unifying view, which, in addition, provides of careful inter-disciplinarity. Special Lectures were devoted to neutrinos in astrophysics and high energy astrophysics. In addition, each Course of this series, introduced and promoted topics or subjects, which, although not being of purely astrophysical or cosmological nature, were of relevant physical interest for astrophysics and cosmology. Deep understanding, clarification, synthesis, careful interdisciplinarity within a fundamental physics framework, werethe maingoals ofthe course. Lectures ranged from a motivation and pedagogical introduction for students and participants not directly working in the field to the latest developmentsand most recent results. All Lectures were plenary, had the same duration and were followed by a discussion. The Course brought together experimentalists and theoretical physicists, astrophysicists and astronomers from a variety of backgrounds, including young scientists at post-doctoral level, senior scientists and advanced graduatestudentsas well.