Wetting has a very long and fascinating history. The solid-liquid interactions are mainly physical, but they are a result of the specific chemistry at the interface. The flow of the liquids in contact with a solid is studied by fluid mechanics, and the solids are described in terms of material science. For about 200 years the basic equations derived from macroscopic arguments and describing the equilibrium configuration of partially wetting liquids have been known, due to Young and Laplace. And starting about 50 years ago, the dynamics of wetting became of central interest. Nowadays, still fundamental question remain unresolved. Most of the open questions find their origin in the fact that wetting depends, to a large extent, on the microscopic characteristics of the considered materials. Youngs equation, for example, has been validated at the microscopic scale only recently.