The document discusses the differences between sex and gender from biological and social perspectives. Biologically, there are anatomical, physiological, genetic, and vulnerability differences between males and females. Socially, gender roles assign responsibilities, behaviors, expectations, power, access, rights, and entitlement that typically assign lower status to women and higher status to men. A gender analysis framework is presented to help identify differences in roles, power imbalances, needs, constraints, and opportunities between males and females to understand how these impact health outcomes like vulnerability to disease and access to care.