This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book provides readers with a holistic guide to regulatory theory and practice—to demystify and make sense of the theoretical literature and to marry it with the real world of regulatory practice. It explains the elements of the regulatory endeavour aided by scientific methods, and makes transparent those elements where judgments are crucial. The book examines a number of conceptual models that aim to explain how public policy is made. It also examines the define stage of the cycle. The book suggests how issues enter the cycle in the first place before proceeding to explore the processes by which the regulatory issue's causes and attributes are diagnosed, and the desired future state—the regulatory objectives—are set. It explores implementation and the processes and strategies by which that regulatory regime is deployed and applied.