Understanding Resolutions, Pixels & Scan Rates
Resolutions
Resolution means the number of pixels (dots), which are points of colour that a display monitor contains. This is expressed in the; number of pixels there are on the width, and the number of pixels on the height, of the display screen.
i.e. 640 x 480 = 680 dots across the screen and 480 dots down the screen.
Different resolutions are: i.e. VGA, SVGA, XGA, SXGA & UXGA
The following table summarizes the categories of screen resolution, as discussed above:
| Width x Height (pixels) |
Video Display Category |
|
640 x 480 |
VGA |
|
800 X 600 |
SVGA |
|
1024 X 768 |
XGA |
|
1280 X 1024 |
SXGA |
|
1600 X 1200 |
UXGA |
What are Pixels?
The pixel is the basic unit of programmable colour on a computer display or image. The physical size of the pixel depends on how the resolution on the display screen has been set. Modern technology has given us the Plasma, LCD & Projector that can now offer a variety of screen settings (resolutions); and screen sharpness is often expressed as dpi (dots (pixels) per inch). Both the screen size and the resolution setting of the screen determine dots per inch - i.e. an image/picture will have a lower resolution (fewer dots per inch) on a large screen because the dots have to spread themselves out over a physical larger area.
Scan Rates
Scan rates are the determined speed of which the screen can redraw a single image it is also referred to as the Refresh Rate. The faster the scan rate (refresh rate) the quicker the re-draw thus less motion artefacts on fast moving action scenes. | 
