The French sociologist Pierre Bordieu defines social capital as "the sum of resources, actual or virtual, that accrue to an individual or group by virtue of possessing a durable network of more or less institutional relationships of mutual acquaintance and recognition." There are different definitions of social capital, but his definition captures the key idea that it is a resource which individuals can utilize to further their goals, but which resides at the level of the community. It is created and fostered by relationships between individuals of a voluntary and nonfinancial nature. This article reviews varying definitions of social capital before going on to examine its origins, which can be traced back to both microlevel or individual, and macrolevel or community-based social processes. Finally, the article examines the effects of social capital on society and policy-making, reviewing the evidence that it has benign effects in relation to economic prosperity, educational attainment, health and welfare, crime reduction, and subjective well-being in communities where it is abundant.