WEBVTT

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Optical storage media.

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Optical storage media is so called because of the way in which data is written to the various media

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types involving the use of different types of lasers on the surface of the disc itself.

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Although it may be somewhat difficult to distinguish various optical discs if there are no default labels

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on them, they do have slight differences in color and hue due to the size of the lasers used to write

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data to them.

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Compact Discs.

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Compact Discs.

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CDs are made of pits and lands noticeable as bumps on the underside of the disc, coated with a thin

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layer of aluminum which results in a reflective surface.

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Data is written in concentric circles, further split up into sectors of 512 bytes, each known as tracks

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on the CD.

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From the inside to the outside or edge of the disc.

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Diameter 120mm.

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Um Type of laser used to write data 780 nanometer annum.

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Infrared laser maximum capacity of a CD 650 to 700 MP.

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The various types of CDs are as follows.

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Compact disc Read only Memory.

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CD-Rom.

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This disc comes with data on it in the form of programs, games, music and so on, and can only be

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read from compact disc recordable Cd-r.

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Data can be written to this disc, but only once.

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Compact Disc Rewritable CD review data can be written to this disc many times.