This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book deals with basic concepts, the legal definition of adoption and related human rights. It overviews the developing relationship between adoption and human rights and identifies the key functions in each body of law. The book considers the social phenomenon of intercountry adoption and outlines the related international framework of treaties and conventions and the associated regulatory bodies. It outlines stages of the adoption process, identifies the interplay between legal function and human rights, as illustrated by reference to European Court of Human Rights (ECtHR) case law. The book focuses on contemporary law, policy and practice: in a common law context, viz. England and the US; in a civil law context, viz. France and Germany; and in an Asian context, viz. Japan and China. It examines current tensions in national adoption law and considers how they relate to specific international human rights.