Not every PC has (or needs) a graphics card. Some PCs have integrated graphics. Integrated graphics chipsets share the system RAM, because they don't have dedicated memory of their own. they are built into the motherboard and are usually installed on low-end systems.This significantly slows down system performance. A modern operating system (OS), such as Microsoft Windows XP, is heavily graphics intensive, so that everyday tasks will seem sluggish.

Lately, however, some big companies such as ATi, Intel, and NVidia have introduced powerful integrated graphics which have advanced technologies trying to balance system memory and graphics memory. These are still no match for a stand-alone graphics card though. Some examples are NVidia nForce 2 Ultra, ATi RADEON IGP (Integrated Graphics Processor), and Intel Extreme Graphics.