Optical disc




In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands (where change from pit to land or from land to pit corresponds to binary value of 1, no change, regardless whether in land or pit area, corresponds to binary value of 0) on a special material (often aluminum ) on one of its flat surfaces.

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Recordable and writable optical discs

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