Definition
A republic is a system of government in which the state is treated as a public affair — the Latin res publica — rather than the private possession of a ruler. Authority is held by citizens and exercised through elected officials and institutions bound by law.
A republic is defined by the absence of a hereditary sovereign and the presence of accountable office-holding, not by the size of the electorate. Republics have ranged from narrow oligarchies to broad modern democracies.
Why it matters
How it works
Classical republics distributed power so that no single person or class could dominate. Roman thinkers praised a mixed constitution combining monarchic, aristocratic, and democratic elements — magistrates, senate, and popular assemblies — each checking the others.
Modern republics keep that logic through written constitutions, separation of powers, regular elections, and an independent judiciary. The decisive features are that office is temporary and accountable, and that legitimacy flows from the citizen body rather than from birth or divine right.