This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book discusses the findings from a recent research study which examined the perspectives of children and young people who received special education provision for their moderate learning difficulties (MLD) in mainstream and special schools. It reviews the nature and quality of social relationships between children with and without learning difficulties in this and other countries. The book deals with questions about the nature of the category, its definition, the terms or labels used and the causal assumptions. It examines who goes to special schools for MLD, the diverse nature of the MLD group, whether research about social and academic outcomes is relevant to the question about inclusion and what recent studies have found with respect to the MLD group. The book also deals with historical issues that relate to relevant education policy and practice in the country.