The meaning of VGA, SVGA and XGA - QS Study
QS Study

Video Graphics Array (VGA): Refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987,1” but through its widespread adoption has also come to mean either an Amplitude Modulated computer display standard, the 15-pin D-sub miniature VGA connector or the 640×480 resolution itself

Super Video Graphics Array (SVGA): Short for Super VGA, a set of graphics standards designed to offer greater resolution than VGA. SVGA supports 800 x 600 resolution, or 480,000 pixels. The SVGA standard supports a palette of 16 million colors, but the number of colors that can be displayed simultaneously is limited by the amount of video memory installed in a system. One SVGA system might display only 256 simultaneous colors while another displays the entire palette of 16 million colors. The SVGA standards are developed by a consortium of monitor and graphics manufacturers called VESA.

Extended Graphics Array (XGA): is a high-resolution video display mode that provides screen pixel resolution of 1,024 by 768 in 256 colors or 640 by 480 in high (16-bit) color. XGA monitor s can be interlaced display s.