Canada is governed by constitutional monarchy and Westminster-style parliamentary democracy. Specifically the government is formulated into the Canadian Crown, an institution which is comprised of an executive, legislative and judicial branch. Each province is one unit within a federation. This formulation was established by Confederation, detailed in the Constitution Act of 1867.
The monarchy is formally the authority of Canada, while the government works as a corporation. This means that the reigning sovereign is the legal governor of the nation, but the executive power essentially rests with what is known as the Queen-in-Council, the executive branch.
For all intents and purposes, practical control over the executive authority of Canada falls to the Prime Minister and the ministers of the Crown, or Cabinet. The Prime Minister is generally the leader of the political party in control of Parliament. This changes if there is a shift in power from a general election or through a vote of non confidence.
The legislature is a bicameral one, with the Crown, the Senate and the House of Commons. The House of Commons is elected by the people via districts for a period of four years. This is the central power of the branch, establishing nearly every law. The Senate is an appointed body, which reviews legislation while the Crown is represented by a viceroy appointed by the monarchy, which finalizes the laws.
Judicial power is held firmly by the Crown. All justice is provided in the Queen’s name. The Supreme Court of Canada is the final court, led by the Chief Justice of Canada. Beneath this is Federal Court, the Federal Court of Appeals and Tax Court of Canada.
According to the constitution and the Crown, the provincial legislatures are limited in the actions in which they can take. They can only pass laws dealing with local matters, provincial officers, municipal governments and charitable institutions. Meanwhile, the federal parliament deals with nearly all other matters, including currency, the military and First Nations.