In computer graphics, antialiasing is a software technique for diminishing jaggies – stairstep-like lines that should be smooth. Jaggies occur because the output device, the monitor or printer, doesn’t have a high enough resolution to represent a smooth line. Antialiasing reduces the prominence of jaggies by surrounding the stairsteps with intermediate shades of gray (for gray-scaling devices) or color (for color devices). Although this reduces the jagged appearance of the lines, it also makes them fuzzier. Another method for reducing jaggies is called smoothing, in which the printer changes the size and horizontal alignment of dotsto make curves smoother. Antialiasing is sometimes called oversampling. (Source: webopedia.com)