The aim of this reference work is to summarize current, fundamental knowledge of interfacial chemistry and bring readers up-to-date with the latest developments. The chemical and physical properties and processes at solid and liquid interfaces are the scientific basis of so many technologies which enhance our present living conditions and will maximize the future survival of mankind. They enable the refinement of chemicals and drug design, nano-scale materials and thin film technologies important in photovoltaic solar energy collection and other electronic devices. The designs of these materials rely more and more on low dimensionality for maximum optimization, i.e. molecular architectures, ultrathin films and wires, and nano-clusters, which are grown on supporting surfaces, and whose properties are decisively determined by their surfaces and interfaces. This so-called "bottom-up" approach rests on a close symbiosis of chemistry, surface science and electrochemistry. The main aim of this Encyclopedia is thus to provide the reader with an interdisciplinary view at the intersection of these three closely related scientific fields.