CD-Rs
CD-Rs are permanent data storage which cannot be erased or overwritten. They have a high performance and high capacity and can be used for a number of different purposes including:

Digital audio mastering, archiving and demos
Multimedia production and recording
Document imaging
Computer data back-up and archiving
Storing music, images, photos, and more

CD-RWs
CD-R re-writables can be recorded onto and rewritten a number of times and the quality will be as good as the first time. They can be used for:

Database backup and archiving
Internet downloads
Audio files
Transporting large files

DVD
DVD is an extremely popular format, which has the advantage of being able to store both audio and video. With the recent release of DVD recorders for the home and office, DVD is a media you simply cannot ignore!

There are a number of different formats of writable and re-writable DVDs available, and they are not compatible with each other, however most modern DVD drives no provide support for the full range of discs and so this is becoming less of an issue.

What is DVD?
A DVD is very similar to a CD, but it has a much larger data capacity. A standard DVD holds about seven times more data than a CD does. This huge capacity means that one DVD has enough room to store a full-length, MPEG-2-encoded feature film, in addition to a lot of other information. DVD can also be used to store almost eight hours of CD-quality music per side.

DVDs are becoming very popular in the office environment, as their large capacity, low cost and ease of use and storage makes them ideal for backing up large amounts of data, and for transferring large files that would require multiple CDs.