These days, CD/DVD burners are standard equipment on almost every new PC. CD/DVD burners that work with discs that can hold 4.7GB of data, and may be used for performing back-ups and storing movies that may be viewed through consumer DVD movie players.
For some time, CDs have provided a convenient way for computer users to distribute data and back up hard drives, but the medium's storage limits of around 700mb per disc in this era of 400GB+ hard drives leaves much to be desired. So if DVD is clearly the way to go, it should be a simple matter to purchase a DVD writer. However, the industry is involved in a war of standards that is yet to be resolved, and early drives were very expensive with some drives costing in excess of £800, now high quality 16x DVD writers can be bought for approximately £20-£50.
On the DVD writing side, there are two main competing standards. The standard known as DVD-R/RW (this is a combination of DVD-R and DVD-RW, note the minus in the name) is supported by Pioneer and other manufacturers and has taken an early lead. The other competing standard DVD+R/RW (this is a combination of DVD+R and DVD+RW, note the "plus" in place of the dash), is being backed by HP and Sony and making a strong bid.
The situation is similar to that of the competing VHS and Beta video standards decades ago. But unlike the videotapes of old, the two main competing DVD standards are designed to create discs that may be read by most consumer DVD movie players. And both standards can read commercial Hollywood DVD movies, as well as work as CD readers and burners.
Both DVD-R and DVD+R let you write a single time to a DVD (similar to CD-R technology). Once you use a DVD-R or DVD+R disc, you can't write data to that disc again. Note that DVD+R capabilities were not available on the first DVD+RW drives from HP and Sony, and drives with this capability are catching up on the market. On the other hand, DVD-RW and DVD+RW technologies let you write continually write to a DVD, just as you can to a CD-RW disc or a floppy.
A third DVD rewritable standard, DVD-RAM, runs a distant third. This technology is incompatible with commercial DVD players-data stored on a DVD-RAM disc can't be read by DVD movie players, or many other DVD drives. The only real use for DVD-RAM is as a high-capacity network backup medium. DVD-RAM discs are housed in cartridges and hold between 2.6 GB and 9.4 GB.
DVD-R and DVD-RW media, as well as DVD+R and DVD+RW media, are generally compatible with newer DVD movie players and DVD-ROM drives on PCs. At the moment, there are differences between manufacturers of different DVD drives, but acceptance of DVD discs by different drives will improve over time. This evolution will probably resemble that of the early days of CD-R and CD-RW drives. You may recall that initially, older CD players couldn't read all the media that newer ones could.
As with Beta versus VHS, DVD standards will eventually iron themselves out. The difference is that whether you choose DVD-RW or DVD+RW, you should, in theory, be able to create DVD discs that can be read by most DVD-ROM drives and DVD movie players. And the more the standards evolve, the stronger this compatibility will become.
More recently there has been a trend for DVD Recorder manufacturers, notably Sony, to by-pass the whole "plus" and "minus" issue by producing machines that work equally happily with both formats.
The crucial difference among the standards is based on which manufacturers adhere to which standards. Similar to the old VHS/Beta tape wars when VCRs first hit the markets, different manufacturers support different standards.
DVD+R, DVD+R Double Dual Layer and DVD+RW
Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha and others support DVD+R and DVD+RW formats.
DVD+R & DVD+R Double Dual Layer is a recordable DVD format similar to CD-R. A DVD+R can only record data once and then the data becomes permanent on the disc. The disc cannot be recorded onto a second time.
DVD+RW is a re-recordable format similar to CD-RW. The data on a DVD+RW disc can be erased and recorded over numerous times without damaging the medium.
Most commercial DVD-ROM players can read DVDs created by a +R/+RW device.
DVD-R, DVD-RW and DVD-RAM
These formats are supported by Panasonic, Toshiba, Apple Computer, Hitachi, NEC, Pioneer, Samsung and Sharp. The DVD Forum also supports these formats.
DVD-R & DVD-R is a recordable DVD format similar to CD-R and DVD+R. A DVD-R can only record data once and then the data becomes permanent on the disc. The disc cannot be recorded onto a second time. There also are two additional standards for DVD-R disks: DVD-RG for general use, and DVD-RA for authoring, which is used for mastering DVD video or data and is not typically available to the general public.
DVD-RW is a re-recordable format similar to CD-RW or DVD+RW. The data on a DVD-RW disc can be erased and recorded over numerous times without damaging the medium.
Most commercial DVD-ROM players can read DVDs created by a -R/-RW device.
DVD-RAM discs can be recorded and erased repeatedly but are only compatible with devices manufactured by the companies that support the DVD-RAM format. DVD-RAM discs are typically housed in cartridges.
DVD-ROM was the first DVD standard to hit the market and is a read-only format. The video or game content is burned onto the DVD once and the DVD will run on any DVD-ROM-equipped device.
BLANK DISC CAPACITIES
DVD-R, DVD-RW, DVD+R & DVD+RW will store 4.7gb or 120 minutes.
DVD+R DVD-R Double Dual Layer discs will store 8.5gb or 240 minutes.
Depending on the quality of video stored a 4.7gb disc can store upto 240 minutes & the 8.5gb Dual Layer discs can store upto 960 minutes.