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CD-RW facts for kids

Kids Encyclopedia Facts
CD-RW bottom
A partly recorded CD-RW. The darker part of the disk (underside) holds the data

A CD-RW is a special type of Compact disc that you can record on and erase many times. The letters "CD-RW" stand for Compact Disc ReWritable. You can save data or music on a CD-RW. Most often, people use them for data. This is because many regular CD players cannot play CD-RWs.

When this technology was first being developed, it was called CD-E. This stood for Compact Disc Erasable. The CD-RW standard was officially introduced in 1997. It replaced an older, less successful type of disc.

How CD-RWs Work

CD-RWs are a kind of optical disc. They use something called Phase change technology to save information. A laser beam heats up tiny spots on the disc. When a spot gets hot, the information stored there can be changed. This is how you can write new data or erase old data.

Manufacturers say you can record and erase a CD-RW up to 1,000 times. They work a lot like CD-Rs. You can write entire "sessions" of data onto them. As long as there is space, you can add new sessions. But for a regular CD player to read the disc, all sessions must be "closed." This means you tell the disc that you are done writing to it.

Why CD-RWs Are Less Common

CD-RWs never became as popular as CD-Rs. There are a few reasons for this. They are more expensive to make and to buy. Also, not all CD players or computer drives can read them. The speeds for reading and writing data are also slower than for regular CDs or CD-Rs.

It's also not very practical to use CD-RWs for quickly adding or removing small files. If you want to delete just one file, you usually have to erase the whole CD. For quick file transfers, other devices like USB flash drives are much better.

Using CD-RWs for Backups

CD-RWs, like CD-Rs, are often used for backups. A backup is a copy of your important files. They are usually cheaper than using tape-based backup systems.

The amount of data a CD-RW can hold varies. It depends on how it's written and the type of disc. Most CD-RWs can store between 500 and 700 megabytes of data.

The same ideas used for CD-RWs are also used for DVD-RWs. DVD-RWs can hold much more data than CD-RWs.

Images for kids

  • CDRW PMA

    Data structure on a CD-RW

See also

Kids robot.svg In Spanish: CD-RW para niños

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