What is VGA ?

VGA stands for Video Graphics Array. It is a graphics display system for PCs developed by IBM. VGA has become one of the de facto standards for PCs. In text mode, VGA systems provide a resolution of 720 by 400 pixels. In graphics mode, the resolution is either 640 by 480 (with 16 colors) or 320 by 200 (with 256 colors). The total palette of colors is 262,144.
Unlike earlier graphics standards for PCs — MDA, CGA, and EGA — VGA uses analog signals rather than digital signals. Consequently, a monitor designed for one of the older standards will not be able to use VGA.
Since its introduction in 1987, several other standards have been developed that offer greater resolution and more colors (see SVGA , 8514/A graphics standard, and XGA), but VGA remains the lowest common denominator. All PCs made today support VGA, and possibly some other more advanced standard.