Hokay, Let me explain the Queen to everybody.
In 1759 there was a battle between the English and the French for the control of Canada, it took place on the Plains of Abraham and the English won. Since then Canada has been closely tied to England and the British empire. We existed as a colony until the 19th century when in 1867 Canada was unified as a country and became a Dominion of the British Empire. That means we were a self governing country but part of the empire and thus had to listen to major decisions etc. Think of how a state is part of the USA, they can make some of their own decisions but if the US goes to war, their soldiers go to, economy helps out etc. Follow me so far...now the way Canada communicated with the Queen and the empire is through the Governor General (that black lady currently).
Following the First World War some things changed. Canada was forced to go to war once the English had declared war on Germany, because we were a dominion, however we could decide how to help and how much to do. The First World War was conflict on a never before seen scale and Canada emerged as one of the most effective groups on the allied side, because of this we gained some power in negotiations with the British Government. Example being Canada told England that if something like Passchendeale ever happened again they would never get another Canadian soldier under their control. Anyway, following the First World War Canada emerged as a commonwealth country, not a dominion. That means we are still part of the empire and associated with the Queen, which is why technically she is our head of state and still has some tasks. However, we are now compleately our own country and can make our own decisions to support or disagree with Britain. This is why we waited 1 day before joining the Second World War.
The current role of the Queen is mostly a ceremonial one, however, Parliament can only be dissolved by her power (exercised by the Governor General) which is why Harper (our PM) had to go to her to perogue parliament recently.
Any questions?