Stands for "Digital Versatile Disc Recordable." A DVD-R looks the same as a regular DVD, but like a CD-R, it can be used to record data. Once a DVD-R has been "burned," or written to, it cannot be written to again. A basic single-sided, single-layer DVD-R disc can store 4.7GB of data. Double-layer discs can store 8.5GB, while double-sided DVD-Rs can store 9.4GB.
DVD-R is the most common format of writable DVDs (compared to the DVD+R and DVD-RAM formats). Most DVD players and DVD-ROM drives can read DVD-R discs. That means you can use a DVD-R disc to back up several gigabytes of data on your computer or make your own video DVD. The Apple SuperDrive used in many Macintosh computers supports the DVD-R format.