How does a Cd keep it's memory and how does it play it's music ?

Question

Like how can a Cd have no power, nothing, just a cd that can hold memory in it. How can it hold Video and Music ?

Answer 1

The data in a CD is fixed - either because it was pressed that way (commercial CD) or was "burnt" ( home made CD) I guess the closest analogy I can think of is a book. Ink printed on the pages of a book is permanent. Your eyes can read the ink - similarly with a CD player, it reads the data on the CD.

Answer 2

Ok, first I will explain how a CD works. When you insert a CD into a CD player, a low power laser in the player is shot directly onto the CD. The CD has minute grooves (underneath the plastic coating on the bottom) that are usually burned in. Either it's burned in or its flat. Where it is flat, the laser beam reflects back off of the CD whereas otherwise it does not. the computer reads this as either
a) it reflected
b) it didnt reflect
Computer 'language' iss binary, which is basically long strings of 1's and 0's. so the CD just reflects these patterns of 1's and 0's and the computer translates them into whatever type of file that is--say a movie.

Answer 3

The CD doesn't keep memory in a chip...information is imprinted on foil which is comressed between plastic. A laser is used to read the data, sort of like a needle on a record.

Answer 4

CD have small holes in them call "pits." as the laser reads the disc it reads the holes as "1's" the lack of a hole is a 0. The data on a CD or any "digital" media is stored as 1's and 0's that operating system inturprets into whatever is stored on the disc via applications (media player, realplayer, itunes ect).