Anoop Verma
You purchased a DVD, but you are unable to write your data on it. Is it possible that something is wrong with the DVD disc or even with your system? Could be. But it is also possible that the DVD disc might not be writeable or re-writeable. There are many different formats of DVD available in the market, some are writeable, some are re-writeable, and some are meant for plain and simple viewing of movies. It is easy to get confused, when there are so many formats in existence.
DVD is short for ‘Digital Video Disc.’ Currently we have five different DVD formats; in case of Blu-ray the number of formats is even larger. The popular DVD formats include – DVD+R, DVD-R, DVD+RW, DVD-RW, and DVD-RAM. DVD-R and DVD+R can record data once, whereas DVD-RAM, DVD-RW, and DVD+RW can be rewritten many times. So many formats exist because different manufacturers tend to adhere to different standards. Often we have instances of what is known as format war, where sections of industry start backing different formats.
After 2003, major tech companies like Sony started offering multi-format DVD players and writers, which are compatible with almost every kind of DVDs available in the market. The newer models of laptops and notebooks are equipped with multi-format DVD systems. If you want to enjoy a video, or record or write something of your own on the DVD, the disc has to be compatible with your needs. Here is a brief view of each of the DVD formats:
DVD-R
This write-once format is compatible with majority of the existing DVD players, recorders and DVD-ROM drives. It can be used only in DVD Recorders and Burners that support DVD-R recording or multi-format recording. Such discs can typically hold 4.7 GB of data or video and that roughly translates into 2 hours of MPEG-2 video on standard (SP) speed setting.
DVD+R
Even though they have been developed separately from DVD-R, the DVD+R discs can record data only once and then the data becomes permanent on the disc. They also hold 4.7 GB of data or video and are compatible with most DVD players and DVD-ROM drives. However, the DVD+R format has some advantages over DVD-R. The DVD+R discs come with better error checking, tracking and speed control features, all of which result in more reliable media, additional session linking methods and fewer damaged discs.
DVD-RW
This format of DVD discs has become quite popular with computer users, as they are re-writeable. The ‘W’ in the name is indicative of the fact that these discs can be written over and over again a number of times. A typical DVD-RW disc can be recorded approximately 1,000 times. They also hold 4.7 GB of data or video and must be used in DVD-RW compatible recorders and burners or multi-format recorders.
DVD+RW
The + format is considered to be more reliable as they have been developed later than the ‘-’ format. This version can record approximately 1,000 times. It also holds 4.7GB of data or video and must be used in DVD+RW compatible Recorders and Burners or multi-format recorders.
DVD-RAM
These are double-sided discs and their storage capacity can go up to 9.4 GB, thus allowing for longer recording times. You can even use it as a separate hard drive, as it supports an incredible 100,000 re-writes. The DVD-RAM disc can be used to record full-length movies, TV shows, music albums and video games. The discs can be re-written again and again many times. However, these discs are compatible with only the latest systems and are used mainly for recording and playback.
Blu-ray
The successor to the DVD technology is already here – it is called Blu-ray. A Blu-ray system uses a 405nm-wavelength blue-violet laser technology, in contrast to the 650nm-wavelength red laser technology used in traditional DVD formats. The re-writable Blu-ray disc, with a data transfer rate of 36Mbps (1x speed) can hold up to 25GB of data on a single-layer disc and 50GB on a dual-layer disc.
