One major factor that differentiates the presidential from the parliamentary system is

The major factor that differentiates the presidential system from the parliamentary system is the separation of powers. In a presidential system, the executive, legislative, and judicial branches are separate and independent of each other. The president, who is the head of the executive branch, is directly elected by the people and has significant powers, including the power to veto legislation passed by the legislature. In contrast, in a parliamentary system, the executive and legislative branches are fused together. The head of government, who is the prime minister, is typically a member of the legislature and is chosen by the legislature. The prime minister has significant power to control the legislative agenda and to pass legislation, but does not have the same level of direct authority over the judiciary. The separation of powers is intended to prevent any one branch of government from becoming too powerful and to ensure that each branch can act as a check on the other branches. This is a key feature of presidential systems and is not present in parliamentary systems.