A presidential system is a form of governance of states. The central person – the head of state and the head of government in one person, is usually a president. So, the system is associated with republics. In most cases, there is no prime minister.
The president holds the executive power. Hence, they are responsible for enforcing the law and the overall governance. Their authority must separate from the legislative and judicial power. Hence, a system of checks and balances must be in place.
The head of government and the head of state is the same person. They gain legitimacy through the popular vote. Thus, the voters directly cast ballots for a given person. Furthermore, assembling the government is in full competency of the president. Lastly, the parliament cannot remove the president.
Another sign of the presidential system is the act of veto. The president can officially stop legislation from the parliament. However, this is reversible. Further, the president also holds a quasi-judicial power – they can pardon sentences.
The main advantage of the system is its stability. Thus, the election terms are very rarely disturbed by votes of no confidence. Secondly, it can respond faster in cases of emergency. However, it has a tendency to be more authoritarian.
The parliament can be unicameral, with only one house – the house of representatives or so. Or bicameral with two houses – a lower house (i.e., House of Representatives) and an upper house (i.e., Senate). Generally, a supreme court holds the judicial review power over the parliament and even the president. Therefore, it can declare laws and other acts unconstitutional.
Presidential system in practice
The presidential system is typical for North and South America. The most famous countries are the United States, Brazil, or Argentina. Only three countries from this region use different forms of government. On the other hand, this system is rare in Europe. A hybrid between this and the parliamentary system is the semi-presidential system.