"Data archiving on CD and DVD
Optical discs are ideal for backup because they offer huge capacity in a format that�s both easy to store and lasts a long time. CDs can hold up to 650MB of data, more than 450 times as much as a floppy disk. DVDs can store a mind-boggling 4.7GB of data, the equivalent of about 18 Zip 250 disks or 3200 floppy disks. (In case you�re interested, that�s a stack of floppies over 40 feet high.) With this kind of capacity, you can easily back up your portfolio, your entire digital photo collection, up to 90 minutes of video or thousands of MP3 files � and store them safely for years."

From this page: http://www.apple.com/powerbook/superdrive.html]