Black is a racialized classification of people, usually a political and skin color-based category for specific populations with a mid to dark brown complexion. Not all people considered "black" have dark skin; in certain countries, often in socially based systems of racial classification in the Western world, the term "black" is used to describe persons who are perceived as dark-skinned compared to other populations. It is most commonly used for people of sub-Saharan African ancestry and the indigenous peoples of Oceania, though it has been applied in many contexts to other groups, and is no indicator of any close ancestral relationship whatsoever. Indigenous African societies do not use the term black as a racial identity outside of influences brought by Western cultures. The term "black" may or may not be capitalized. The AP Stylebook changed its guide to capitalize the "b" in black in 2020. The ASA Style Guide says that the "b" should not be capitalized. Some perceive the term "black" as a derogatory, outdated, reductive or otherwise unrepresentative label, and as a result neither use nor define it, especially in African countries with little to no history of colonial racial segregation.

Contemporary anthropologists and other scientists, while recognizing the reality of biological variation between different human populations, regard the concept of a unified, distinguishable "Black race" as socially constructed. Different societies apply different criteria regarding who is classified "black", and these social constructs have changed over time. In a number of countries, societal variables affect classification as much as skin color, and the social criteria for "blackness" vary. In the United Kingdom, "black" was historically equivalent with "person of color", a general term for non-European peoples. In other regions such as Australasia, settlers applied the term "black" or it was used by local populations with different histories and ancestral backgrounds.