Democracy (Greek: δημοκρατία, dēmokratiā, from dēmos 'people' and kratos 'rule') is a form of government in which the people have the authority to deliberate and decide legislation ("direct democracy"), or to choose governing officials to do so ("representative democracy"). Who is considered part of "the people" and how authority is shared among or delegated by the people has changed over time and at different rates in different countries, but over time more and more of a democratic country's inhabitants have generally been included. Cornerstones of democracy include freedom of assembly, association and speech, inclusiveness and equality, citizenship, consent of the governed, voting rights, freedom from unwarranted governmental deprivation of the right to life and liberty, and minority rights.

The notion of democracy has evolved over time considerably. The original form of democracy was a direct democracy. The most common form of democracy today is a representative democracy, where the people elect government officials to govern on their behalf such as in a parliamentary or presidential democracy.Prevalent day-to-day decision making of democracies is the majority rule, though other decision making approaches like supermajority and consensus have also been integral to democracies. They serve the crucial purpose of inclusiveness and broader legitimacy on sensitive issues—counterbalancing majoritarianism—and therefore mostly take precedence on a constitutional level. In the common variant of liberal democracy, the powers of the majority are exercised within the framework of a representative democracy, but the constitution limits the majority and protects the minority—usually through the enjoyment by all of certain individual rights, e.g. freedom of speech or freedom of association.The term appeared in the 5th century BC to denote the political systems then existing in Greek city-states, notably Classical Athens, to mean "rule of the people", in contrast to aristocracy (ἀριστοκρατία, aristokratía), meaning "rule of an elite". Western democracy, as distinct from that which existed in antiquity, is generally considered to have originated in city-states such as those in Classical Athens and the Roman Republic, where various schemes and degrees of enfranchisement of the free male population were observed before the form disappeared in the West at the beginning of late antiquity. In virtually all democratic governments throughout ancient and modern history, democratic citizenship consisted of an elite class until full enfranchisement was won for all adult citizens in most modern democracies through the suffrage movements of the 19th and 20th centuries.

Democracy contrasts with forms of government where power is either held by an individual, as in autocratic systems like absolute monarchy, or where power is held by a small number of individuals, as in an oligarchy—oppositions inherited from ancient Greek philosophy. Karl Popper defined democracy in contrast to dictatorship or tyranny, focusing on opportunities for the people to control their leaders and to oust them without the need for a revolution. World public opinion strongly favors democratic systems of government.