Modern "combo" drives can write to almost all disc formats (DVD-R, DVD-RW, DVD+R, DVD+RW, CD-R, CD-RW). Older drives write only their DVD format, so you may have to get DVD+R/RW discs for a DVD+RW drive and DVD-R/RW discs for a DVD-RW drive.

The DVD+RW format has a few advantages when used in a computer, but if data backup or access speed is important, also consider the DVD-RAM format. DVD-RAM is fast and reliable, and the discs have an optional cartridge to help protect data. Most DVD-RAM drives also write DVD-R/RW discs, and some "super combo" drives write all three formats.

The information below will explain about each format of DVD :

What is DVD-R ?

DVD-R (which is pronounced "dash R" not "minus R") uses organic dye technology, like CD-R, and is compatible with most DVD drives and players. First-generation capacity was 3.95 billion bytes, later extended to 4.7 billion bytes. Matching the 4.7G capacity of DVD-ROM was crucial for desktop DVD production. In early 2000 the format was split into an "authoring" version and a "general" version. The general version, intended for home use, writes with a cheaper 650-nm laser, the same as DVD-RAM. DVD-R(A) is intended for professional development and uses a 635-nm laser. DVD-R(A) discs are not writable in DVD-R(G) recorders, and vice-versa, but both kinds of discs are readable in most DVD players and drives. The main differences, in addition to recording wavelength, are that DVD-R(G) uses decrementing pre-pit addresses, a pre-stamped (version 1.0) or pre-recorded (version 1.1) control area, CPRM, and allows double-sided discs. A third version for "special authoring," allowing protected movie content to be recorded on DVD-R media, was considered but will probably not happen.

What is DVD-RW ?

DVD-RW (formerly DVD-R/W and also briefly known as DVD-ER) is a phase-change erasable format. Developed by Pioneer based on DVD-R, using similar track pitch, mark length, and rotation control, DVD-RW is playable in many DVD drives and players. (Some drives and players are confused by DVD-RW media's lower reflectivity into thinking it's a dual-layer disc. In other cases the drive or player doesn't recognize the disc format code and doesn't even try to read the disc. Simple firmware upgrades can solve both problems.) DVD-RW uses groove recording with address info on land areas for synchronization at write time (land data is ignored during reading). Capacity is 4.7 billion bytes. DVD-RW discs can be rewritten about 1,000 times.

What is DVD-RAM ?

DVD-RAM, with an initial storage capacity of 2.58 billion bytes, later increased to 4.7, uses phase-change dual (PD) technology with some magneto-optic (MO) features mixed in. DVD-RAM is the best suited of the writable DVD formats for use in computers, because of its defect management and zoned CLV format for rapid access. However, it's not compatible with most drives and players (because of defect management, reflectivity differences, and minor format differences). A wobbled groove is used to provide clocking data, with marks written in both the groove and the land between grooves. The grooves and pre-embossed sector headers are molded into the disc during manufacturing. Single-sided DVD-RAM discs come with or without cartridges. There are nine types of cartridges. Discs can only be written while in the cartridge. Double-sided DVD-RAM discs were initially available in sealed cartridges only, but now come in removable versions as well. Cartridge dimensions are 124.6 mm x 135.5 mm x 8.0 mm. DVD-RAM can be rewritten more than 100,000 times, and the discs are expected to last at least 30 years.

What is DVD+RW and DVD+R ?

DVD+RW is an erasable format based on CD-RW technology. It became available in late 2001. DVD+RW is supported by Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha, and others. It is not supported by the DVD Forum (even though most of the DVD+RW companies are members), but the Forum has no power to set standards. DVD+RW drives read DVD-ROMs and CDs, and usually read DVD-Rs and DVD-RWs, but do not read or write DVD-RAM discs. DVD+RW drives also write CD-Rs and CD-RWs. DVD+RW discs, which hold 4.7 billion bytes per side, are readable in many existing DVD-Video players and DVD-ROM drives. (They run into the same reflectivity and disc format recognition problems as DVD-RW.)

DVD+RW backers claimed in 1997 that the format would be used only for computer data, not home video, but this was apparently a smokescreen intended to placate the DVD Forum and competitors. The original 1.0 format, which held 3 billion bytes (2.8 gigabytes) per side and was not compatible with any existing players and drives, was abandoned in late 1999.

The DVD+RW format uses phase-change media with a high-frequency wobbled groove that allows it to eliminate linking sectors. This, plus the option of no defect management, allows DVD+RW discs to be written in a way that is compatible with many existing DVD readers. The DVD+RW specification allows for either CLV format for sequential video access (read at CAV speeds by the drive) or CAV format for random access, but CAV recording is not supported by any current hardware. DVD+R discs can only be recorded in CLV mode. Only CLV-formatted discs can be read in standard DVD drives and players. DVD+RW media can be rewritten about 1,000 times (down from 100,000 times in the original 1.0 version).