Dvd

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Short info about DVD.

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Dvd

  1. 1. Dvd<br />Digital Versatile Disc<br />Presented By<br />Ehtisham Ali<br />
  2. 2. What is DVD?<br />A DVD is a disc that is used for storing information that a computer can read. <br />This can be a movie, music, television program or a computer game. <br />DVDs look like compact discs as they are the same size but they store much more information in a different way.<br />
  3. 3. Who invented it?<br />The DVD was not invented by one person or company. Toshiba, Philips, Sony, and Matsushita Electric all helped to develop the technology used to make DVDs.<br />
  4. 4. How does it get power?<br />A DVD player is powered by electricity. <br />It reads the data on the media using a light called a laser.<br />
  5. 5. ?<br />How does it work?<br />DVDs are of the same shape and thickness as CDs, and they are made using some of the same materials and manufacturing methods. <br />Like a CD, the data on a DVD is held in the form of small pits and bumps on the disc. <br />A DVD is made of several layers of plastic. <br />Each layer is made by injection molding plastic. <br />This forms a disc that has tiny bumps arranged as a single very long spiral track of data. More on the bumps later.<br />
  6. 6. ?<br />How does it work?<br />CONTD…<br />Each writable layer of a DVD has a spiral track of data. <br />On single-layer DVDs, the track always circles from the inside of the disc to the outside. <br />That the spiral track starts at the center means that a single-layer DVD can be smaller than 12 centimeters if desired.<br />
  7. 7. How dangerous is it?<br />The DVD is not dangerous by itself unless it is broken. <br />Then the pieces are very sharp and could cut your fingers - or your feet if you step on them.<br />
  8. 8. What does it do?<br />It records digital information that can be used by a DVD player or computer.<br />
  9. 9. How does it vary?<br />The first DVDs could store around 4.5 Gigabytes, but later scientists found a way to make more layers so they could store more data.<br /> These are called "double layer" DVDs. But now there are two new types of DVDs called blu-ray and HD-DVD that store even more.<br />
  10. 10. How has it changed the world?<br />The DVD has modernized the current generations of video playing devices into the digital age.<br />
  11. 11. tHANKS<br />

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