Many types of problems caused by land degradation can be documented worldwide. The main natural resources affected are soils, water, natural vegetation, and wildlife; but cultivated plants are exposed to even greater damage, which poses a threat to food security as well. Soil degradation is one of the most crucial processes of land degradation and environmental change. Over a quarter of the world's agricultural land has been damaged by long-term soil degradation, corresponding to one-tenth of the earth's land surface. As is well known, mountain areas are especially vulnerable to land degradation (Figure 1). Because mountains are also water towers, providing water not only for highland areas but also for the surrounding lowlands, land degradation in the mountains has serious impacts on the global supply of freshwater and on growing water-related conflicts. At the same time, there have been many achievements in sustainable land use and in avoiding and combating degradation (Figure 2). Every day land users and soil and water conservation (SWC) specialists evaluate experience and generate know-how related to land management, improvement of soil fertility, and protection of soil resources. Most of this valuable knowledge, however, is not well documented or easily accessible, and comparison of different types of experience is difficult. The World Overview of Conservation Approaches and Technologies (WOCAT) has the mission of providing tools that allow SWC specialists to share their valuable knowledge in soil and water management, assist them in their search for appropriate SWC technologies and approaches, and support them in making decisions in the field and at the planning level.