Affirmative action refers to a set of policies and practices designed to address past and present discrimination against historically disadvantaged groups, primarily based on race, ethnicity, gender, religion, or national origin. The core purpose of affirmative action is to promote equality of opportunity and achieve diversity in areas such as education, employment, and government contracting.

These policies aim to counteract systemic biases and the lingering effects of historical injustices that have created barriers for certain groups. Mechanisms can include preferential treatment in admissions to universities, hiring processes, or the allocation of scholarships and contracts. Proponents argue that affirmative action is necessary to create a level playing field, ensure representation, and enrich society through diversity. Critics, however, often contend that such policies lead to 'reverse discrimination,' compromise meritocracy, and can stigmatize beneficiaries. Despite ongoing debates, affirmative action remains a significant tool in many countries for fostering social equity and inclusion.