The images that appear on your monitor (screen) come from a piece of equipment in your computer called a video card. There are three basic criteria for selecting a good video card: the amount of onboard RAM, the manufacturer, and the bus type.
The amount of RAM you need on your video card is relative to your monitor size. For a 15-inch monitor, 2MB is sufficient; for a 17-inch monitor, 4MB is the right amount.
Bus or interface refers to the type of slot that the video card fits into inside your computer. ISA is an older style bus, while PCI and AGP are the current technologies.
There are dozens of video card makers but only a handful are considered industry standard, top-performing products. The leading video card makers you should consider are Matrox, Diamond, Number Nine, and ATI.
When purchasing your new system, insist on at least 2MB of Video RAM, a PCI or AGP interface, and make sure the card is manufactured by Matrox, Diamond, Number Nine, or ATI.