This book proposes two simple quantum mechanical models for the analytical description of metal surfaces and nanoparticles. It gives an ostensive picture of the forces acting in a metal surface and deduces analytical formulae for the description of their physical properties. This book explains the relation between near-surface stress and familiar surface parameters. The concept of the separation of the three-dimensional body into three one-dimensional subsystems was applied. The content is of interest to all those working in the field of surface physics.