I see these two terms used quite interchangeably. Not sure if they do mean the same thing.
A French Canadian would be someone who is Canadian but has some ancestral roots in France in the same way as an Irish Canadian is a Canadian with some ancestral roots in Ireland.
A Quebecois would be someone who was born and raised in Quebec or at least has spent a significant portion of his/her life in Quebec.
Est-ce une interprétation correcte?