This chapter describes market coupling in detail and guides the reader through the evolution of market coupling in Europe. The chapter lays out the underlying market coupling principles and highlights the benefits of EU market coupling and cross-border interconnectors. Single Day-Ahead Coupling and Single Intraday Coupling processes are introduced at a high level, as well as the roles and responsibilities of major market participants. The Terms, Conditions, and Methodologies, which are developed to ensure a harmonized approach to market coupling, as well as the market coupling timeframes, are briefly introduced. Finally, a number of high-level examples are provided to illustrate how market coupling works.