An accessible yet rigorous discussion of the thermodynamics of surfaces and interfaces, bridging the gap between textbooks and advanced literature by delivering a comprehensive guide without an overwhelming amount of mathematics. The book begins with a review of the relevant aspects of the thermodynamics of bulk systems, followed by a description of the thermodynamic variables for surfaces and interfaces. Important surface phenomena are detailed, including wetting, crystalline systems (including grain boundaries), interfaces between different phases, curved interfaces (capillarity),...