Antialiasing
From ColorWiki
Antialiasing is a technique used to smooth the edges of line art, fonts, and other vector art by blending the edges of the object with its background and creating intermediary colors and shades. Technically it lowers the resolution of the image but done correctly, and viewed from sufficient distance, can appear to smooth previously jagged edges and actually increase the apparent resolution. It is a good technique for screen display (CD-ROM and Web publishing) but should not be used for printing in most cases as the higher resolution of a printing device will often reduce jaggies and antialiasing would make it look worse.
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