Scan frequency:
Horizontal scan frequency : The number of lines illuminated on a video screen in one second. For example, a resolution of 400 lines refreshed 60 times per second requires a scan rate of 24 kHz plus overhead (time to bring the beam back to the beginning of the next line). Same as horizontal sync frequency in TV. Contrast with vertical scan frequency.
Vertical scan frequency : Also called "refresh rate," it is the number of times an entire display screen is refreshed, or redrawn, per second. Measured in Hertz, display systems typically range from 56Hz to well over 100Hz. A minimum of 70Hz is recommended to help prevent eye strain. Contrast with horizontal scan frequency.

 

 

SDRAM (Synchronous Dynamic Random Access Memory):
A memory type, that is faster than DRAM. It synchronizes all memory access requests according to the microprocessor's internal clock.

 

 

Shading:
The process of interpolating color within the interior of a polygon, or between the vertices of a line, during rasterization.

 

 

Sideband signalling:
This is an extra 8-bits of transfer capability built into AGP so that an AGP graphics board can request information at the same time as it is receiving other information.

 

 

16-bit/64-bit:
1. The processing power of a chip or system. The processor can handle this many bits of information at once.
2. May also designate the width of a bus or data path.
3. Used to describe graphics power (e.g. 16-bit color = 65,000 colors).

 

 

Specular reflexion (specular highlighting):
In a 3D image, reflections of light sources on shiny materials, such as metal.

 

 

Sprite:
A 2D on-screen graphic object. It is possible to manipulate it without affecting the background images.

 

 

Stencil buffer:
This is an extra buffer containing special information concerning pixels as to whether to draw them or not. Its feature is particularly useful in creating special effects such as shadowing from multiple light sources. These buffers calculate a cutout effect, masking part of an image to apply a more precise transformation to the rest. Another function would be to mask part of an image so that the chip only calculates the rest.

 

 

SVGA (Super Video Graphics Array):
A graphics standard starting from display resolutions of 640x480 at 256 colors.