The video card processes all graphics related work (especially 3D) and delivers the resultant output to a connected display/monitor. Video card improvements move along at breakneck speeds - a new generation of video cards often replaces the old within 3-6 months. The GPU (Graphics Processing Unit) basically determines the features (e.g. DirectX/OpenGL, HDR, and SLI or CrossFire) and performance level of a video card. Besides the GPU, the video memory specs (including video memory type, size and clock speed), interface (AGP or PCI Express), and I/O ports are should all be taken into account before purchasing a video card.