This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book focuses on clarifying the implication of different approaches to development for settlement policy. It provides the three primary objectives. The chapter first describes and compares the elements of the major approaches to development which have emerged over the past three decades. It secondly analyses to bring about a closer tie between interventionist development theory and settlement theory by exploring the implications for settlement policy of different approaches to development. The chapter thirdly discusses to identify and clarify the major debates surrounding the use of settlement policies in national and regional development. It considers social, political and economic conditions, provided the basis for the emergence of new approaches to development. The chapter examines 'developing' and 'developed' to distinguish between poorer and richer nations.