1 00:00:00,110 --> 00:00:01,640 Optical storage media. 2 00:00:02,150 --> 00:00:07,520 Optical storage media is so called because of the way in which data is written to the various media 3 00:00:07,520 --> 00:00:12,650 types involving the use of different types of lasers on the surface of the disc itself. 4 00:00:12,830 --> 00:00:18,320 Although it may be somewhat difficult to distinguish various optical discs if there are no default labels 5 00:00:18,320 --> 00:00:24,260 on them, they do have slight differences in color and hue due to the size of the lasers used to write 6 00:00:24,260 --> 00:00:25,190 data to them. 7 00:00:25,460 --> 00:00:27,140 Compact Discs. 8 00:00:27,440 --> 00:00:28,760 Compact Discs. 9 00:00:28,790 --> 00:00:35,210 CDs are made of pits and lands noticeable as bumps on the underside of the disc, coated with a thin 10 00:00:35,210 --> 00:00:38,780 layer of aluminum which results in a reflective surface. 11 00:00:39,110 --> 00:00:47,180 Data is written in concentric circles, further split up into sectors of 512 bytes, each known as tracks 12 00:00:47,180 --> 00:00:47,880 on the CD. 13 00:00:47,900 --> 00:00:51,260 From the inside to the outside or edge of the disc. 14 00:00:51,290 --> 00:00:54,530 Diameter 120mm. 15 00:00:54,570 --> 00:01:00,120 Um Type of laser used to write data 780 nanometer annum. 16 00:01:00,150 --> 00:01:07,830 Infrared laser maximum capacity of a CD 650 to 700 MP. 17 00:01:08,100 --> 00:01:10,950 The various types of CDs are as follows. 18 00:01:11,070 --> 00:01:13,890 Compact disc Read only Memory. 19 00:01:13,930 --> 00:01:15,330 CD-Rom. 20 00:01:15,510 --> 00:01:21,960 This disc comes with data on it in the form of programs, games, music and so on, and can only be 21 00:01:21,960 --> 00:01:26,010 read from compact disc recordable Cd-r. 22 00:01:26,280 --> 00:01:29,550 Data can be written to this disc, but only once. 23 00:01:29,790 --> 00:01:37,050 Compact Disc Rewritable CD review data can be written to this disc many times.