The idea of introducing this handbook derives from the realization that tourism is often the object of a single-issue analysis, lacking an organic vision. The fact that this complex phenomenon manifests itself in space meant in concrete terms and presents economic-territorial implications of varied nature privileges those who inquire it mainly from a territorial point of view, like economic geographers. The approach followed, while enhancing the three most important 'moments' in which tourism occurs, i.e. the outgoing, the movement and the incoming, is applicable both on a regional, or even local level, and on a general scale, thus allowing to make those abstractions than many scholars believe to be fundamental to the definition of their discipline as a real science.