Book excerpt: Millions of human beings the world over survive in conditions of poverty and social exclusion, and this is unlikely to change in the years to come. This grave situation affects the whole of humanity, which cannot and must not shut its eyes to it. Social exclusion is spreading so much that it is becoming one of the keys to understanding the economic and social situation of the world today. This book attempts to deciper the concept of social exclusion. It aims to identify, analyse and measure exclusion and make it more visible. It also aims to provide a detailed overview of those involved and their initiatives.