We have not touched on the integrated graphics solutions. Some motherboards using chipsets from Intel, Nvidia and SiS have graphics processing capabilities integrated into the motherboard itself, obviating the need for a graphics card.
Integrated graphics are perfectly fine if all you ever want from your PC is to use productivity applications and surf the Web. They can save you a good deal of money.
They tend to fall down a bit when it comes to 3D graphics, however. They use system memory instead of dedicated graphics memory, and they usually do not perform nearly as well as discreet graphics cards.
Often, a motherboard with integrated graphics will still have an AGP or 16x PCIe slot into which you can insert a graphics card. In this case, inserting a graphics card will often override the integrated graphics capabilities of the motherboard (sometimes on older models you may have to disable it manually through the BIOS. See your motherboard manual for details). These motherboards are good buys - you can run them without a discreet graphics card for a while, but if you find you need to upgrade, you can purchase a graphics card at any time.
For more on integrated graphics and motherboards generally, we suggest you take a look at our Motherboard Buying Guide