DEFINITION:

Also see frame, raster graphics, and raster image processor.

The term raster refers to the region of a cathode ray tube (CRT) or liquid crystal display (LCD) monitor that is capable of rendering images.

In a CRT, the raster is a sequence of horizontal lines that  … 
Definition continues below.

GRAPHICS SOFTWARE DEFINITION (continued): …  are scanned rapidly with an electron beam from left to right andtop tobottom, in much the same way as a TV picture tube is scanned. However,there arecertain differences. In general, the resolutionis better in a computer CRT than in a TV picture tube. Also, a TV rasterscan is interlaced, while the raster scan in a computer CRT is almost always non-interlaced. In a CRT, the raster is slightly smaller than the full screen size of the monitor. Theheight and width of the raster can be adjusted, as can the horizontal andvertical position. Other parameters … 
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