The compact disc has changed the way we listen to music, and has enabled many new things to become available using it as a medium to transmit data to a computer. The compact disc, or CD, was first released in 1982 by Phillips and Sony, after being developed by James T. Russell. At this time, the CD was not very popular, as the players were expensive, as were the CDs, and there was not a wide amount of music available on them. Billy Joel’s “52^nd Street” was the first recording released on a CD. The CD was much more durable than the vinyl records being used at the time, and was smaller and more convenient. By 1993, the CD had the largest part of the market for music. To read the information contained on a CD, a laser receives electrical impulses by bumps on the CD track which are 125 nanometers high. Each track is 0.5 microns wide, with 1.6 microns separating each track. If the track were to be unrolled from the CD, it would be over 5 miles long. As the CD begins to be read from the middle, it is spun at 500 revolutions per minute. As the laser works its way out towards the edge, it slows to 200 rpm, so as to keep the flow of data constant. Because there is no actual contact between the laser and the CD, each CD should last for lifetimes. The CD has greatly changed how we listen to music. It has enabled music to be digitized at a high quality, instead of the poor quality received with vinyl records. Also, the CD has been used for data storage by computers, and has enabled us to transfer games and other programs in a much more convenient manner than the hundreds of floppy disks it would take to hold the contents of one CD.