Video cards (video boards / video display boards / graphics cards / graphics adapter) is a physical hardware circuit board(s) which connects to the Motherboard. When the video card is connected to a monitor it serves as the visual link between you and your computer, allowing you to view and manage your computers software data.
Typical Video Card Connectors
VGA (Video Graphics Adapter) use to connect analog monitors
to the motherboard (Integrated Video Card)
Expansion Bus Chart:
Typical nVidia PCI-e Card
X - is a collection of API’s for handling tasks related
to Multimedia and Microsoft Platforms.
VGA vs. SVGA vs. XGA
All video cards use VGA routines to generate basic display to interact with a PCs system BIOS. Then, any advancement on these routines with no universal standard to speak about, to generate display and color above 640x480 with 16 colors is considered SVGA or XGA. I believe I can state without exception all video cards sold in nearly a decade would be considered SVGA or XGA (LCD and Laptops), capable of displaying a larger realm of color and resolution than basic VGA or 640x480 - 16 colors.
Video Memory vs. Video Speed
One of the most misunderstood components of a video card is the Video Memory. Video memory does not equate to Video speed. Video speed is determined by two major factors: the chipset on the video card and the I/O slot holding the video card, (ISA. PCI, AGP, PCI-e). Video memory only determines the ability to display a certain color depth and resolution, such as 800x600-16million colors. There exists a mathematical formula to determine the required amount of memory on a video card to display varying degrees of color and resolutions, but let us suffice to say that a four (4MB) video card can display 1024x768-16million colors all that is required to work with photographic 2D images. Since it is rare today to find any video cards with less than 4MB/s of memory, this is not really much of an issue.
Video Card Default Resolution and Color support
video graphics adapter
extensive Graphics Adapter (LCD and Laptops)
Wide Ultra XGA
special thanks to ATI and nVidia