Well… maybe this is a big whoosh…
But to clear a couple of things up:
One: There is no Jean Poutine. The Prime Minister of Canada is, at the moment, Jean Chrétien. Poutine is a dish made of potatoes, cheese, and meat gravy, named after a military officer who first had it made (Capitaine Poutine).
Two: Canada does not have a president. We do have a Prime Minister, and also a Queen. The Queen, too busy with her other, more favourite countries, is represented in Canada by a Governor-General.
That being said, many functioning democracies today do have a Prime Minister, and a President, all at the same time. Usually, the Prime Minister is the head of an elected legislature (a Congress, a House of Commons, a Parliament, a National Assembly) and the President is an independent figure, either elected directly, or appointed by an elected official or committe of some sort. There are many variations of this division of powers.
For example:
France has President Jacques Chirac, and PM Jean-Pierre Raffarin
Poland has President Aleksander Kwasniewski and PM Leszek Miller
Italy has President Carlo Azeglio Ciampi and PM Silvio Berlusconi
Each country, based on the way its democracy is contrived, uses the offices of President and PM diferently. And some of them have their roles filled by others- Canada’s Governor-General, Germany’s Chancellor. It;s likely, for example, that you are more familiar with the President of France than the PM, but I’d expect you to have heard the Italian PM’s name before that of the president.