The video card, as its name indicates is the component the computer whose role is to transmit data on the screen in the control of a microprocessor dedicated and integrated into the card. It is this microprocessor that calculates the position of points on the screen and processes the texture of restitution algorithms for display complex images such as those generated by video games.
Of course, the video card is more quality; more information is processed and displayed quickly.
On a laptop, the video card is not a real card as on many desktops, but rather a set of chips combined into a dedicated integrated circuit display and called "video chipset."
Internal memory of video cards
The video card processor need external resources to process the information it receives, it is the video memory, expressed in megabytes. There are at present video cards 128, 256, or 512 MB for the most powerful laptops.
This memory allocated to the video processor can be integrated with the map video itself or shared. In the latter case, the amount of memory required for video processing is taken from RAM the computer.
For example, a computer with 512 MB of RAM and a graphics card with 128 MB shared will not actually use that 384 MB of RAM. This has the effect of making your PC slightly less efficient.
Video cards with integrated memory rather than shared are course more expensive and are intended to benefit more use playful as office.