Authoritarian regimes differ from democracies primarily in governance structure and citizen participation. In authoritarian systems, power is concentrated in a single leader or group, limiting political freedoms and dissent. Decision-making is often opaque, with little to no public input. Conversely, democracies prioritize popular sovereignty and institutions that promote freedom of expression, allowing citizens to engage in governance through elections and open discourse. These characteristics are essential for political legitimacy and social stability.