digital versatile disc
Originally referred to as digital video discs, these high-capacity optical discs are now used to store everything from massive computer applications to full-length movies. While similar in physical size and appearance to a compact disc or a CD-ROM, DVD is a huge leap from its predecessor's 650MB of storage. A standard single-layer, single-sided DVD can store a whopping 4.7GB of data. But it doesn't stop there--DVD also has a two-layer standard that boosts the single-sided capacity to 8.5GB. And there's more! DVDs can be double-sided, ramping up the maximum storage on a single disc to 17GB. Unfortunately, to use DVDs, you'll have to buy a new drive, but that new hardware will also read your older CD-ROMs and audio CDs.
see also: CD-ROM