3D cards existed before but NVIDIA was the first company to coin the term GPU. A couple of years later, ATi tried to popularize the term VPU (visual processing unit), but that effort failed as everyone continued to use the term GPU.
August 31, 1999 marked the introduction of the graphics processing unit (GPU) for the PC industry—the NVIDIA GeForce 256. The technical definition of a GPU is "a single-chip processor with integrated transform, lighting, triangle setup/clipping, and rendering engines that is capable of processing a minimum of 10 million polygons per second."
With transform, lighting, setup, and rendering on a single GPU, the GeForce 256 delivers 15M polygons/second and 480M pixels/second of performance. Truly revolutionary, its unique 256-bit rendering engine enabled an order of magnitude increase in visual complexity, and helped to set the stage for the future of realism in graphics.