A graphics processing unit (GPU) on the same chip as the central processing unit (CPU).  The GPU is a programmable logic chip (processor) specialized for display functions.  See 
logic chip, 
GPU and 
integrated graphics.
An Integrated GPU
This Trinity chip from AMD integrates a sophisticated GPU with four cores of x86 processing and a DDR3 memory controller.  Each x86 section is a dual-core CPU with its own L2 cache.  (Image courtesy of Advanced Micro Devices, Inc.)