So why is the operating system providing peripherals this information? What's provided will be used for tracking...

Maybe I’m confusing it too. I searched “Wacom tablet” and it seems to be a... tablet.

Wacom produces multiple devices, the simplest are basically a pen based touchpad. No display and no real computing power, needs to be plugged into a computer to function in any way. The more high end ones are a pen touchpad+display but still requires a computer (ie: they're a monitor). There are also standalone tablets that use Wacom technology although I'm not sure offhand if Wacom makes any directly.

You can buy tablet computers from Wacom, I have a “Wacom Mobile Studio” gathering dust that I really should get rid of someday. Just didn’t fit into my art workflow better than a laptop and an old Wacom Intuos 4 stuffed into the bag next to it.

They do mostly make external pen input devices, with or without screens. Which people have been calling “drawing tablets” since loooong before “tablet computer” was a phrase anyone used outside of maybe science fiction.

A Wacom tablet is what used to be called a digitizer tablet, ie, a HID that uses a pen and a surface to allow for easier and better drawing. Essentially an odd-shaped mouse with some extra pressure sensitivity.

GP must have confused with the currently better known use of tablet, which is a full-blown computer with touch screen and no keyboard.

You could think of it as more like a touchscreen computer monitor. They don't run standalone.