Computer display standards are a combination of aspect ratio, display size, display resolution, color depth, and refresh rate. They are associated with specific expansion cards, video connectors and monitors. History Various computer display standards or display modes have been used in the history of the personal computer. They are often a combination of aspect ratio (specified as width-to-height ratio), display resolution (specified as the width and height in pixels), color depth (measured in bits per pixel), and refresh rate (expressed in hertz). Associated with the screen resolution and refresh rate is a display adapter. Earlier display adapters were simple frame-buffers, but later display standards also specified a more extensive set of display functions and software controlled interface. Beyond display modes, the VESA industry organization has defined several standards related to power management and device identification, while ergonomics standards are set by the TCO. Standards A number of common resolutions have been used with computers descended from the original IBM PC. Some of these are now supported by other families of personal computers. These are de facto standards, usually originated by one manufacturer and reverse-engineered by others, though the VESA group has co-ordinated the efforts of several leading video display adapter manufacturers. Video standards associated with IBM-PC-descended personal computers are shown in the diagram and table below, alongside those of early Macintosh and other makes for comparison. (From the early 1990s onwards, most manufacturers moved over to PC display standards thanks to widely available and affordable hardware). Display resolution prefixes Although the common standard prefixes super and ultra do not indicate specific modifiers to base standard resolutions, several others do: Quarter (Q or q) A quarter of the base resolution. E.g. QVGA, a term for a 320×240 resolution, half the width and height of VGA, hence the quarter total resolution. The "Q" prefix usually indicates "Quad" (4 times as many, not 1/4 times as many) in higher resolutions, and sometimes "q" is used instead of "Q" to specify quarter (by analogy with SI prefixes m/M), but this usage is not consistent. Wide (W) The base resolution increased by increasing the width and keeping the height constant, for square or near-square pixels on a widescreen display, usually with an aspect ratio of either 16:9 (adding an extra 1/3rd width vs a standard 4:3 display) or 16:10 (adding an extra 1/5th). However, it is sometimes used to denote a resolution that would have