The concepts of sustainability and tourism are both highly complex. Tourism is defined by the activities of travellers and all related economic sectors as well as the resulting effects on the environment and society. Sustainability, on the other hand, encompasses at least the three dimensions of environment, social affairs and economy, and sometimes also other dimensions such as management. 

The paper deals with the question of how tourism can be classified and described in the context of sustainability. It also presents models and concepts for measuring and rating sustainability in tourism. Furthermore, it presents which governance instruments are available for sustainability in tourism.