This chapter discusses the effect of disability on biopsychosocial functioning throughout the lifespan, the effect of culture, race, and ethnicity on behaviors, attitudes, and identity, and the effects of discrimination and stereotypes on behaviors, attitudes, and identity. It describes the influence of sexual orientation on behaviors, attitudes, and identity, the impact of transgender and transitioning process on behaviors, attitudes, identity, and relationships, and systemic (institutionalized) discrimination (e.g., racism, sexism, ageism). The chapter then explains the principles of culturally competent social work practice, sexual orientation concepts, gender and gender identity concepts, and social and economic justice. It elaborates the effect of poverty on individuals, families, groups, organizations, and communities, the impact of social institutions on society, criminal justice systems, and the impact of globalization on clients/client systems (e.g., interrelatedness of systems, international integration, technology, environmental or financial crises, epidemics).