This glossary addresses eight key questions about health inequalities: (1) What is the difference between health inequality and health inequity? (2) Should we measure health inequalities or social group differences in health? (3) Do health inequalities mainly reflect poverty or the socioeconomic gradient? (4) Are health inequalities mediated by material deprivation or psychosocial mechanisms? (5) Does relative income affect health independently of absolute income? (6) Do health inequalities between places reflect those between social groups or suggest a contextual effect of place? (7) What is the contribution of the life course to health inequalities? (8) What kinds of inequality should we study? Health inequality refers to differences in health outcomes among individuals and groups, while health inequity refers to unfair or unjust health differences. Health inequality is a descriptive term, not necessarily implying moral judgment, whereas health inequity involves a moral commitment to social justice. Health inequalities can be influenced by poverty, socioeconomic gradients, material deprivation, psychosocial mechanisms, relative income, and contextual factors. The distinction between health inequality and health inequity lies in the normative judgment involved in determining whether inequalities are unjust. Measuring health inequalities can be done by examining social group differences or by analyzing the distribution of health status across individuals. The choice between these approaches reflects the distinction between "inequality" and "inequity." The socioeconomic gradient in health refers to the worse health of those at lower socioeconomic levels, regardless of individual circumstances. This gradient is influenced by material conditions, psychosocial factors, and relative income. The absolute and relative income hypothesis suggests that health is influenced by both individual income and relative income compared to others. Place or context plays a significant role in health inequalities, with both collective and contextual effects. Collective effects relate to aggregated group properties, while contextual effects involve broader social, cultural, and institutional factors. The life course perspective highlights how early life experiences influence health outcomes in adulthood. Health inequalities can also be influenced by ascriptive characteristics such as gender and race, as well as other social and economic factors. The study of health inequalities is complex and involves multiple factors, including social determinants, individual behaviors, and contextual influences.This glossary addresses eight key questions about health inequalities: (1) What is the difference between health inequality and health inequity? (2) Should we measure health inequalities or social group differences in health? (3) Do health inequalities mainly reflect poverty or the socioeconomic gradient? (4) Are health inequalities mediated by material deprivation or psychosocial mechanisms? (5) Does relative income affect health independently of absolute income? (6) Do health inequalities between places reflect those between social groups or suggest a contextual effect of place? (7) What is the contribution of the life course to health inequalities? (8) What kinds of inequality should we study? Health inequality refers to differences in health outcomes among individuals and groups, while health inequity refers to unfair or unjust health differences. Health inequality is a descriptive term, not necessarily implying moral judgment, whereas health inequity involves a moral commitment to social justice. Health inequalities can be influenced by poverty, socioeconomic gradients, material deprivation, psychosocial mechanisms, relative income, and contextual factors. The distinction between health inequality and health inequity lies in the normative judgment involved in determining whether inequalities are unjust. Measuring health inequalities can be done by examining social group differences or by analyzing the distribution of health status across individuals. The choice between these approaches reflects the distinction between "inequality" and "inequity." The socioeconomic gradient in health refers to the worse health of those at lower socioeconomic levels, regardless of individual circumstances. This gradient is influenced by material conditions, psychosocial factors, and relative income. The absolute and relative income hypothesis suggests that health is influenced by both individual income and relative income compared to others. Place or context plays a significant role in health inequalities, with both collective and contextual effects. Collective effects relate to aggregated group properties, while contextual effects involve broader social, cultural, and institutional factors. The life course perspective highlights how early life experiences influence health outcomes in adulthood. Health inequalities can also be influenced by ascriptive characteristics such as gender and race, as well as other social and economic factors. The study of health inequalities is complex and involves multiple factors, including social determinants, individual behaviors, and contextual influences.