What is the difference between VGA, SVGA and UXGA?

The terms VGA, SVGA, XGA, SXGA, UXGA etc., all relate to the resolution a monitor supports.

The video format is the same despite the different designations and as an example a UXGA monitor can Display resolutions from VGA all the way up to UXGA. In all cases they use the same HD15 connector (below images) and VGA and SVGA cabling.

Male HD15 Connector
HD15 Male Interface image
Female HD15 Connector
HD15 Female Interface image

Regardless of what resolution a Monitor or Video Card is able to support, they are commonly referred to as just being VGA, the naming conventions listed above never really caught on with the general public and thus even the most High End 3-D Graphics card from Companies like NVIDIA or ATI will have what they term a VGA port (in addition to a DVI port in many cases) even though the card may output resolutions greater than 1920 x 1440.

Some High End Monitors support resolutions up to 2048x1536 @ 79Hz, which is still part of the same Multisync format and is backwards compatible to lower resolutions. Most High End Monitor Manufacturers don't mention VGA, SVGA etc at all, they typically refer to Monitors as CRT's, LCD's or Plasma Displays and list the maximum resolution that they support and at what refresh rate.

The relationship is as follows:

*Legacy Resolutions no longer supported (included only for reference)
Code Resolution
*(Color Graphics Adapter) CGA 320 x 200
*(Enhanced Graphics Adapter) EGA 640 x 350
(Video Graphics Array) VGA 640 x 480
(Super Video Graphics Array) SVGA 800 x 600
(High Definition Television 720i/p) HDTV 1280 x 720
(Extended Graphics Array) XGA 1024 x 768
(Wide Extended Graphics Array) WXGA 1366 x 768
(Super Extended Graphics Array) SXGA 1280 x 1024
(Super Extended Graphics Array+) SXGA+ 1400 x 1050
(Wide Super Extended Graphics Array) WSXGA 1600 x 1024
(Wide Super Extended Graphics Array+) WSXGA+ 1680 x 1050
(High Definition Television 1080i/p) HDTV 1920 x 1080
(Ultra Extended Graphics Array) UXGA 1600 x 1200
(Wide Ultra Extended Graphics Array) WUXGA 1920 x 1200
(Quad Extended Graphics Array) QXGA 2048 x 1536
(Quad Super Extended Graphics Array) QSXGA 2560 x 2048
(Wide Quad Super Extended Graphics Array) WQSXGA 3200 x 2048
(Quad Ultra Extended Graphics Array) QUXGA 3200 x 2400
(Wide Quad Ultra Extended Graphics Array) WQUXGA 3840 x 2400
(Hex Super Extended Graphics Array) HSXGA 5120 x 4096
(Wide Hex Super Extended Graphics Array) WHSXGA 6400 x 4096
(Hex Ultra Extended Graphics Array) HUXGA 6400 x 4800
(Wide Hex Ultra Extended Graphics Array) WHUXGA 7680 x 4800