There is a continuing need for disaster risk reduction strategies to shift emphasis from assessing hazard events toward reducing vulnerabilities within social systems. Conceptualizing and measuring social vulnerability is an important stage along this path. Our current understanding of vulnerability is guided by theories, methodologies, and measurement standards derived from different schools of thought. This chapter provides a summary of core concepts on vulnerability, and its measurement from a social perspective (i.e., social vulnerability). The chapter has three main sections that delve into (1) conceptual frameworks for hazards vulnerability, 2) approaches for measuring social vulnerability, and 3) a case study analysis of social vulnerability in Hurricane Sandy.