Parliamentary System: A parliamentary system is a form of government where executive power resides in a legislative body (parliament) and is led by a prime minister or similar figurehead. The executive branch is accountable to parliament and can be removed through votes of no confidence.
Presidential System: A presidential system is a form of government where executive power is vested in an elected president who serves as both head of state and head of government. The president's term is fixed and separate from the legislature, providing stability but less direct accountability to parliament.
Authoritarian Regime: An authoritarian regime refers to a type of government characterized by strong central control, limited political freedoms, restricted civil liberties, censorship, and lack of competitive elections. Power rests with an individual or small group who exercise significant control over all aspects of governance.