 Health inequalities exist among individuals from different backgrounds and social groups, with dimensions including global, country or state, and geographic levels. Theories attempt to explain group-level differences in health, while concepts such as relative versus absolute, dose-response versus threshold, composition versus context, place versus space, life-course perspective on health, causal pathways to health, conditional health effects, and group-level versus individual differences are vital in understanding health inequalities. The article reflects on what makes health inequalities unjust and considers policies that prioritise eliminating disparities versus raising overall health standards. This article was authored by Marianna C. Arkaya, Alyssa L. Arkaya and SV Subramanian.