What Does Extended Graphics Array (XGA) Mean?
Extended Graphics Array (XGA) is a computer display standard that provides 1,024 by 768 pixels in 256 colors, or 640 by 480 pixels in 16-bit color. It is a proprietary standard that was originally intended to replace the earlier VGA (Video Graphics Array) display mode, but as it was quickly replaced by superior technology, it instead became simply known as part of the VGA family (with other formats like SVGA and UVGA).
Techopedia Explains Extended Graphics Array (XGA)
IBM developed VGA in 1987, and XGA followed in 1990. While VGA was limited to a standard resolution of 640 by 480 in 16 colors, XGA had the ability to increase color depth at that resolution to 16-bit, or to increase to a higher resolution of 1,024 by 768 in 256 colors. Although this was a drastic improvement in image quality, it was quickly superseded by a number of other display modes. Nevertheless, the format has evolved into newer standards such as Wide XGA (WXGA), which is used for modern low-end high definition displays.