Conceptual framework for understanding the sustainability of social-ecological systems: Indices and frameworks of indicators on sustainable development are used for observing how sustainable a social- ecological system is, though they are not appropriate to understand why these systems can be sustainable. We develop a conceptual sketch based on the concept of social-ecological resilience, which is the foundation of sustainable systems. Thus, we draw on concepts such as perturbations, adaptive capacity, and state and regime shifts, for arguing mechanisms and elements involved in generation of social-ecological resilience of systems.