In a parliamentary system, the head of government is typically selected indirectly by the legislature, rather than directly by the populace. The specific process varies by country, but generally involves the party or coalition holding a majority of seats in the parliament designating their leader as the prime minister. For example, in the Westminster system, the monarch formally appoints the prime minister, but this appointment is based on the convention that the individual must command the confidence of the House of Commons.
This method of selection ensures that the head of government enjoys the support of the legislative branch, promoting stability and facilitating the passage of legislation. Historically, this evolved as a way to balance power and ensure accountability of the executive to the representatives of the people. This process contrasts with presidential systems, where the head of government and state is chosen directly by voters, leading to a greater separation of powers.