A CD Writer is simply a CD-ROM drive that can save information to recordable CDs (CD-R or CD-RW). A DVD Writer is similar to a CD Writer, although it can also save information to recordable DVDs (DVD-R or DVD-RW).
CDs/DVDs are flexible because they can be used in many different types of players (computer, home stereo, etc.) and can hold up to 700MB (CDs) or 4.5GB (DVDs) of data. Recordable CDs are very cheap, making them an economically smart solution for backing up your data.
For most Windows users recording is easier than ever. In both cases you will begin by simply putting the blank media in and then dragging the media you want to burn onto the CD/DVD icon. You then click the icon and choose to burn the media to disc.
For information on other ways to backup data please see FAQs: How do I backup data to a USB Memory Key? and How Do I Use My Network Space (H drive) That Has Been Given to Me By UNC? ; or see article Data Backup Solutions.