A presidential system is a system of government where an executive branch is headed by a president who serves as both head of state and head of government.In such a system, the President enjoys independent power ad is not responsible to the legislature.
A presidential system separates the executive and legislative functions of the government and provides what are commonly called checks and balances to limit the power of both the executive and the legislature. In a parliamentary system, the legislature holds the power, and the executive must answer to the legislature.
In the Presidential system, executive has a fixed tenure normally, the executive head (President) stays in power for the whole term. It is not easy to remove him from power through impeachment. In the Parliamentary system, the tenure of the executive is not fixed. The Council of Ministers is dismissed if it loses the confidence of the legislature before its tenure is over.