Black people is a term used in certain countries, often in socially based systems of racial classification or of ethnicity, to describe persons who are perceived to be dark-skinned compared to other populations. As such, the meaning of the expression varies widely both between and within societies, and depends significantly on context. For many other individuals, communities and countries, "black" is also perceived as a derogatory, outdated, reductive or otherwise unrepresentative label, and as a result is neither used nor defined.
Different societies apply differing criteria regarding who is classified as "black", and these social constructs have also 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 South Africa and Latin America, mixed-race people are generally not classified as "black". In other regions such as Australasia, settlers applied the term "black" or it was used by local populations with different histories and ancestral backgrounds.