(a) parliamentarianism; It is a system of government in which there exists a Head of State who performs ceremonial functions and a Head of Government who performs executive functions.
(b) i. There is separation of powers in the presidential system, while there is fusion of powers in the parliamentary system.
ii. In the presidential system, the President chooses his ministers from outside parliament, whiles in the parliamentary system Ministers are chosen from parliament.
iii. In a presidential system, the Head of State is also Head of Government while in the parliamentary system, the Head of State is different from Head of Government.
iv. In a presidential system, the President can be removed by impeachment while in the parliamentary system, the Prime Minister can be removed through a vote of no confidence.
v. In a presidential system, the President is directly elected while in the parliamentary system; the Prime Minister is appointed from the majority party in parliament.
vi. In a presidential system, the role of the opposition is not constitutionally determined but in the parliamentary system, the constitution provides a role for the opposition in parliament.
vii. In a presidential system, ministers are individually accountable to the president but in the parliamentary system, the ministers are collectively responsible to parliament.
viii. In a presidential system, there is fixed tenure for the government but in parliamentary system, there is flexibility in the tenure of the government.
ix. In a presidential system, party discipline is weak whiles in the parliamentary system, party discipline it rigidly enforced.
x. There is constitutional supremacy in the presidential system, whereas there is parliamentary supremacy in the parliamentary system.
xi. In a presidential system of government, the President can veto bills passed by the legislature whereas in the parliamentary there is no such veto.