This chapter examines the key features of modern democracy, as well as its origins. It first explains what democracy means in the field of comparative politics, before discussing different models of democracy, including presidential democracy, parliamentary democracy, and democracies oriented towards consensus or majoritarian rule. It then describes the conditions—economic and political, domestic, and international—that allow some countries to become democratic but preserve others under the rule of dictatorships. In particular, it analyses the variables that facilitate the democratization of dictatorships and the factors that place democracies at risk of becoming authoritarian regimes. Finally, it reflects on the future of democracy and looks at the challenges that lie ahead for new generations of citizens.