Canada is a constitutional monarchy. The Queen, represented by the Governor General, is the head of state and the Prime Minister is the head of Government. The U.S. is a republic. The head of state and head of the Government are the same person: the President.
Canada and the United States are both democratic, federal states. Our countries share many cultural similarities, but very different structures, processes and laws govern each country. Perhaps the greatest distinction lies in our constitutions. The American Constitution consists of a single written document (the Constitution of the United States of America). Canada’s constitution is made up of both written elements (British and Canadian statutes, as well as court judgments) and unwritten elements (traditions, customs and conventions).