Cosmology has dramatically evolved during the last decade and there has been vast development of, e.g., theories of galaxy formation in connection with the early universe or gravitational lensing. These new developments motivated the editors to organize a school covering all of these ideas and observations in a pedagogical way. The topics covered in the 26 lectures of this summer school include: QSO absorption systems, identification of objects at high redshift, radiogalaxies, galaxy formation and evolution, galaxy number counts, clustering, theories of structure formation, large-scale structure and streaming motions, gravitational lensing, and spectrum and anisotropies of the cosmic microwave background radiation. Observational developments, data analysis, and theoretical aspects are equally treated.

These review articles by outstanding specialists cover the present status ofthe observations of the spectrum and of the anisotropies of the cosmic microwave background radiation. Experimental developments, data analysis and related theoretical aspects are also treated. The idea is to review and discuss at a level accessible to non-specialised astronomers and graduate students the most recent developments in this field as well as the future perspectives for astrophysics and cosmology in particular.