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.

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.