In computing, specifically computer hardware, a controller is a chip or expansion card that interfaces with a peripheral device. This may be a link between two parts of a computer or a controller for an external device hat manages the operation of that device.
Graphic Adapter Cards
A Graphic Adapter Card or more commonly known as a video card is an expansion card which generates a feed of display to an output (a monitor). A Video Card of GPU can relieve stress from the CPU especially during intensive programs like video gaming.