1) the conditions in which people are born, grow, live, work and age, including the health system. These circumstances are shaped by the distribution of money, power and resources at global, national and local levels, which are themselves influenced by policy choices. The social determinants of health are mostly responsible for health inequities - the unfair and avoidable differences in health status seen within and between countries. 2) life-enhancing resources, such as food supply, housing, economic and social relationships, transportation, education, and health care, whose distribution across populations effectively determines length and quality of life. Social determinants of health broadly include both societal conditions and psychosocial factors, such as opportunities for employment, access to health care, hopefulness, and freedom from racism. These determinants can affect individual and community health directly, through an independent influence or an interaction with other determinants, or indirectly, through their influence on health-promoting behaviors by, for example, determining whether a person has access to healthy food or a safe environment in which to exercise. Policies and other interventions influence the availability and distribution of these social determinants to different social groups, including those defined by socioeconomic status, race/ethnicity, sexual orientation, sex, disability status, and geographic location. Principles of social justice influence these multiple interactions and the resulting health outcomes: inequitable distribution of social determinants contributes to health disparities and health inequity, whereas equitable distribution of social determinants contributes to health equity.