The latest developments in particle physics are inextricably linked to modern cosmology. The main purpose of this Enrico Fermi school was to emphasise the complex interconnection between cosmolgy and particle physics, on both the theoretical and experimental sides. Unifying theories in high energy physics and inflationary models of the universe are therefore treated side by side. The large scale structure of the universe is analysed by confronting recent observations with theoretical models. The IRAS infrared surveys, the measurements in the cosmic background radiation and the consequences of these for our understanding of the universe are extensively dealt with.