What is the main differences between a Parliamentry and Presidential systems?

Parliamentry and Presidential systems are two of the most common governmental systems used. The two oldest and most prominent examples of these systems are the British and American systems respectively. The main difference between the two is the separation of powers in an American system and the fusion of powers within the British systems. Separation of powers is the idea that the three branches of government, the executive who proposes and implements the law, the legislature who passes the law and the judiciary who interprets the law. In America, the executive which is embodied by the President is elected independently and cannot be a member of the legislature, the Bicameral Houses of Congress who is also elected and both houses are equal. In order for legislation to pass, it must go through both Houses of Congress and be signed by the President, who also has a veto on all legislation. However it can be difficult to pass legislation when the President is of a different party to one or both Houses of Congress, as partisan differences can lead to legislation being compromised or blocked by any of the houses or the President. An example of this gridlock was when Paul Ryan after taking control of both Houses of Congress attempted to repeal the Affordable Care Act, also know as Obama care, something President Obama would not agree to leading to gridlock. This is as the Founding Fathers intended to limit the power of both branches of government and prevent tyranny. This leads to limited government but also gridlock and powerless government being unable to fulfil their electoral promises.The Parliamentary system is very different. Instead of dividing up power to ensure limited government, the executive all have to be members of the legislature in the British case the House of Common or the House of Lords. This means that in order to be the government, the executive has to have a majority of support of the Hosue of Commons or it would collapse. This leads to to executive's in Britain led by the Prime Minster being singifcantly stronger than their American counterparts and being able to pass any legislation they want provided their party supports it. An example of this would be Boris Johnson passing the EU Withdrawl Act 2020 without having to listen to the oppostion who opposed it because he has an eighty strong majoirty in the House of Commons. In America, if either of the houses or President opposed the Bill it would fail, showing thr strrength of the British Executive.Overall the Main difference, although not only, between the two systems if the princple of seperation of powers which leds to a weaker executive under a Presidential system than the strong executive of a Parliamentry system.