whow does a cd-rw works?

Answer 1

The surface of the CD is a mirror, and the bumps disrupt the mirror's perfect surface. The laser that reads the CD can detect the difference between a perfect mirror and an imperfection caused by a bump because of the difference in reflectivity. By interpreting "perfect mirror" as a "1," and "bump" as a "0," it is easy to store digital information on a CD. The bumps on a CD are molded into the plastic when it is manufactured, so they are permanent.

To create a writeable CD (CD-R), you need to modify the surface of a CD so you can burn data onto it, turning it into a CD-R. There are no bumps on a CD-R. A clear dye layer covers the CD's mirror. A write laser heats up the dye layer enough to make it opaque. The read laser in a CD player senses the difference between clear dye and opaque dye the same way it senses bumps -- it picks up on the difference in reflectivity.

To create a rewriteable CD (CD-RW), you need a dye layer that can be changed back and forth between opaque and transparent. This page discusses the special material that CD-RW's use. The material has the property that it can change its transparency depending on temperature. Heated to one temperature, the material cools to a transparent state; heated to another temperature, it cools to a cloudy state. By changing the power (and therefore the temperature) of the writing laser, the data on the CD can be changed, or "rewritten."

A CD-R can be read by just about any CD player. CD-RW discs are not so versatile -- lots of older CD players cannot read them.

For more details go to -
http://electronics.howstuffworks.com/framed.htm?parent=question655.htm&url=http://www.pctechguide.com/09cdr-rw.htm

Answer 2

unlike a cd-r, a cd-rw has the ability to record over previously recorded data. Think of it like a blank tape casette. But once a cd-r has recorded information to it, it is permanent. Cd-rw's are more expensive, but can save you money if you find yourself throwing out a lot of burned cd's.

Answer 3

The surface of a CD-RW is 'softer' than a CD-R, so it can be melted and reformed again.

So, a CD-R is like clay (once it's been put in a kiln)
and a CD-RW is like play-doh (as long as you keep the cap on).

Answer 4

CD-Rs have the optical layer coated by non-magnetic substances and data once burnt in it cannot be erased or re-written. But in a CD-RW it is made of magnetic substances and the layer can be made flat(erased) or pattern can be changed for many number of times

Answer 5

A cd-rw is like a regular cd-r but the cd-rw can be erased and rewritten onto..a cd-r is permanent after you burn something on it..

Answer 6

in a rewriteable (RW) CD, a UV Ray can erase the content on the cd

Answer 7

The same as a CD-R (recordable once) except that a CD-RW (re-writable) can have it content deleted, and then re-written, like a video tape.

Answer 8

Actually I could spend a lot of time telling you how it works and you'll probably be bored. At one point I asked the same question and the best website I found to answer it is listed below.

I'm not trying to advertise, but for the ease of explanation this website was a good resource....

Answer 9

It is a CD-Rewritable, and that means that you can write music onto it, but then you don't like it and you can later write different music over that music, deleting the old music. Is that what you wanted to know?