This chapter introduces the reader to the concept of dual-class stock, describing it as a company capital structure that enables a founder to crystallise its investment in the company at IPO, and generate equity funding for growth, while retaining control.This short chapter continues with a brief outline of the target audience, and the structure and contents of the book, before delineating the scope.The scope, as explained in the Introduction, is limited to dual-class stock in the context of publicly listed companies, and where dual-class stock is implemented to allow a controller to retain control with a disproportionately lower level of equity.Finally, the Introduction summarises some of the terminologies used in the book to inform the reader of the common terms and phrases used throughout.