The role of the president differs significantly between presidential and parliamentary systems. In a presidential system, the president is both the head of state and government, often possessing considerable executive power. North America exemplifies this, where the president operates independently of the legislature. Conversely, in a parliamentary system, the head of government (often a prime minister) is typically elected from the legislative body and is dependent on its support to govern. This structure emphasizes collaboration between branches, often leading to more cohesive policy-making.