Book excerpt: "Surfaces and Interfaces of Solids" emphasizes both experimental and theoretical aspects of surface and interface physics. Beside the techniques of preparing well-defined solid surfaces and interfaces basic models for the description of structural, vibronic and electronic properties ofinterfaces are described, as well as fundamental aspects of adsorption and layer growth. Because of its importance for modern microelectronics special emphasis is placed on the electronic properties of semiconductorinterfaces and heterostructures. Experimental topics covering the basics of ultrahigh-vacuum technology, electron optics, surface spectroscopies and electrical interface characterization techniques are presented in the form of separate panels.