Since the late 1980s, social theorists championed for the birth of a new era, in which societies were increasingly exposed to growing global risks. The presence of increasing risks including natural disasters, technological errors, terrorist attacks, nuclear wars and environmental degradation suggests that human beings are becoming increasingly vulnerable. Therefore, an understanding of vulnerability is crucial. Vulnerability is often considered as the potential to suffer from physical attacks. This approach, however, has limited capacity to explain many forms of suffering including not only physical aspects, but also mental, social, economic, political and social dimensions. This chapter draws on the vulnerability literature to present an overarching framework for the book. It starts with an outline of the concept origins, then discusses its relationship with the risk society thesis before forming conceptualisation. The chapter then points out the key similarities and differences between vulnerability and other concepts such as risk, disaster, poverty, security and resilience. The authors rework an existing βsecurityβ framework to develop a new definition of the concept of vulnerability. Finally, the authors look into the root causes and the formation of vulnerability within social systems.