Essential Guide to Computer Data Storage: From Floppy to DVD, The

DVD

What is a DVD?

It looks like a CD, but it has a much higher density of recording.

DVD still uses the optical recording technology (like a CD), but it has smaller pit length, closer tracks, larger data area of the disc, and other features that result in significantly larger storage capacities. Single-sided, single-layered DVD-ROM can store 4.7 GB of data versus about 670 MB for a CD-ROM. But instead of just playing music, it delivers more than two hours of high-quality video. A single-sided, single-layer DVD can contain up to 133 minutes of video, enough to handle 95% of all movies, without the interruption for flipping the disc over or changing discs. Because DVD can deliver more than 500 lines of horizontal resolution, the picture detail ...