Every Canadian province carries its own distinct history. If you have yet to be lucky enough to step foot into every province, or thread through every Canadian town or city, be sure to anticipate a sense of wonder every time you visit a new corner in this vast country.
Case in point: Oakville, Ontario. The province of Ontario has the highest population in the entire nation, hovering just below thirteen million people (The highest population density, however, goes to Prince Edward Island, with a density of 24.7 people per kilometer square. Now that is a tight squeeze!) Still, anyone who lives in any other province will most definitely notice the population difference in Ontario compared to their home-province.
Oakville has a population of 180,000 people. Seems like a small number compared to Toronto's 2.5 million. Nonetheless less, Oakville is still very much a bustling and robust town. With arts and jazz festivals, museums, libraries, and annual corporate events in Oakville, the town has grown to be its own, albeit smaller, metropolitan. Frankly, Oakville (and the rest of the principle areas of the GTA) can function quite independently from the city of Toronto. That is not to say that they should, but only that they could, further illustrating Oakville's self-sufficiency.
Although each of the five areas within the GTA function somewhat independently from each other they are still close enough to each other that the citizens can cross over and enjoy the different events, facilities and services that each have to offer. In fact, each area runs on their own transit system. Oakville, in particular, runs on Oakville Transit, which offers above-ground (no subway) transportation services. The multiple transit systems across the GTA can seem confusing at first, but when looked at from a practical perspective, they do offer a level convenience that residents would have otherwise. Those who opt to drive their car through the GTA will also find it relatively easy, seeing as how major highways interconnect the GTA regions. For example, a resident of Milton wouldn't see an issue in working in Toronto or being a guest at wedding in Oakville. The areas are so close to each other, and are connected by transit systems, that it is very easy to get from one end of the GTA to the other.