The resolution of a screen states it's measurements in pixels. A resolution is given in two numbers, the first one giving the number of pixels in each line of pixels, the second one giving the numbers of such pixel lines.
Also, for certain display configurations standards were introduced and given names, such as i.e. VGA. They are usually but not always associated with one specific resolution.
|resolution||short name||long name|
|standard screen resolutions (4:3)|
|320x240||QVGA||Quarter Video Graphics Array (IBM)|
|640x480||VGA||Video Graphics Array (IBM)|
|800x600||SVGA||Super Video Graphics Array|
|1024x768||XGA||eXtended Graphics Adapter|
|1280x1024||SXGA||Super eXtended Graphics Adapter / Array|
|1400x1050||SXGA+||Super eXtended Graphics Adapter / Array Plus|
|1600x1200||UXGA||Ultra eXtended Graphics Adapter|
|2048x1536||UXGA||Quad eXtended Graphics Adapter|
|widescreen resolutions (8:5)|
|854x480||WVGA||Wide Video Graphics Array|
|1024x600||WSVGA||Wide Super Video Graphics Adapter / Array|
|1366x768||WXGA||Wide eXtended Graphics Adapter|
|1440x900||WXGA+||Wide eXtended Graphics Adapter Plus|
|1600x900||WSXGA||Wide Super eXtended Graphics Adapter / Array|
|1600x1024||WSXGA||Wide Super eXtended Graphics Adapter / Array|
|1680x1050||WSXGA+||Wide Super eXtended Graphics Adapter / Array Plus|
|1920x1200||WUXGA||Wide Ultra eXtended Graphics Adapter / Array|
(*) SXGA 1280x1024 is actually 5:4 ratio, not 4:3.