Blank DVDs are used for backing up computer files and for storing recordable media, whether it is in the form of photos, music or text files. There are several different DVD formats from which to choose. The oldest is DVD-R, introduced in 1997. Other major formats are DVD+R, DVD-RW and DVD+RW and each has something different to offer.
The "R" in DVD-R stands for "recordable" while formats that end in RW are "rewritable." A DVD-R can be used to record video or audio, but once it has been written to it is not possible to erase it or overwrite it. They are used for archiving files you want to keep, transferring files between PCs or sending large files to friends. A standard DVD-R holds up to 4.7GB of data, while a dual layer DVD-R will hold 8.5GB.
DVD-R is the most compatible format and can be read by practically all DVD players. They can be read by DVD drives in computers, portable DVDs and home DVD players. They cost a little less than DVD+R, and are significantly cheaper than RW DVDs. The dual layer versions offer almost twice the storage of rewritable discs, which is a further saving of both money per disc and the number of discs required.
The major drawback to DVD-Rs is that they can only be written to once. Most people prefer to put routine system backups and temporary files onto a rewritable disc, which can be rewritten up to about 1,000 times. The other minor disadvantage is that although you can read a DVD-R with either a --R or +R drive you can only write to it with a -R type drive. This is not really a problem as all modern drives are compatible with both systems.
Is DVD-R the Best Format?
The best format is the one most suitable for the job at hand. If you want permanent storage then R format is preferable to RW because it is less expensive and holds more data. If you only want to store data temporarily then it is better to use a rewritable disc, which has a higher initial cost but the cost per use will be cheaper. DVD-R is great for sending photo files to friends or archiving data. With most modern disc drives compatible with --R and +R formats this is not a serious issue.