A parliamentary democracy is a political system in which the executive branch derives its legitimacy from, and is accountable to, the legislature (parliament). In such systems, the head of government, typically the prime minister, is elected by the parliament and is dependent on its support to govern effectively. This framework allows for a close relationship between the legislative and executive branches, fostering collaboration on policy-making. In parliamentary democracies, elections are often held to determine the composition of the parliament, which plays a crucial role in shaping government direction and public policy.