Aerodromes in Canada may or may not have a control tower, whose occupants issue clearances and instructions to improve the safety and efficiency of movement in the vicinity of the airport. The controllers are also usually good for a cup of coffee if you're stuck at an airport with no open restaurants.
Think for a moment about the size of the CFS. It's about four centimetres thick, filled with lightweight newsprint pages, often two or three aerodromes to a page. That's a lot of aerodromes. How many do you think have control towers?
The answer is in this link.
I have to admit that I thought there were many more. I guess if I'd then tried to list them, I would have concluded that there weren't that many, but I hadn't realized the true size of the ratio of uncontrolled to controlled facilities in Canada. It goes to show how freely air traffic moves here. Aerodromes without control towers, are called "uncontrolled," but movements there are controlled by rules and procedures dictating how pilots approach and leave the airport, select a runway, and communicate with one another. Pilots coordinate their movements over the radio, and don't swear at each other nearly as much as car drivers would, equipped with the same technology. Americans have taken to calling such airports "non-towered" to emphasize the fact that they are not uncontrolled free-for-alls. There are a number of airports in Canada that have control towers but are uncontrolled, because the control tower has been closed.
And the airplanes in the sample conversations with air traffic services on that site are real airplanes, and I've flown one of them.