Full Form of DVD :
Digital Video Disc (or) Digital Versatile Disc
DVD Full Form can either be termed as Digital Video Disc or Digital Versatile Disc. This technology uses an optical media to store the digital data. Though a DVD is similar to a CD in size, the storage capacity of the DVD is quite large. There are different types of DVD depending on the usage. Some are used to store different data types like computer files and software programs while others are exclusively formatted to support video playback.
The format of DVD-video was originally standardized during 1995 by the association of a group of electronic giants like Panasonic, Sony, Philips, Toshiba, etc. Even there is a dual-layer DVD with data stored in two layers on one side of the disc. One of the significant features of a DVD drive is that it is backward compatible and thus can play even old CD-ROMs, video CDs, CD-I disks, etc.
DVD Full Form – Additional Information
Data storage can be a big issue on the computer, especially if it happens to be videos and to some extent audios. Videos occupy a lot of space on the hard disk and thus there is always a threat of the disk space running short. Initially, people used CDs (compact discs) to transfer and store their data. However, the capacity of CD’s was not good enough to transfer large amount of data at a time. Hence, DVDs or digital video disc or currently known as “digital versatile disc” came into existence.
Types of DVDs
There are different types of DVDs available in the market and their capacity to store data varies accordingly. These are single-sided single-layer (most commonly used), single-sided double layer, double-sided single and very rarely used type of double-sided double layer. The respective capacities of data storage of these DVDs are 4.7 GB, 8.5 GB, 9.4 GB and 17.08 GB. In the most basic DVD one can store more than 4-5 movies. Initial CDs had only capacity of 750 MB; this would mean only 1 movie per disc.
The quality of the recording of CD and DVD is also different. DVD uses a laser diode light wavelength of 650 nm with contrast to 780 nm used by CD. This shorter wavelength is responsible for accurate data transfer in greater quantity, thus enabling more data to be written on a DVD. However, the latest Blue-ray disc outdoes the performance of DVD and uses a wavelength of 405 nm and stores up to 50 GB of data.
What are the different formats of DVDs?
DVD is a generalized term for a disc that stores data externally. Nonetheless, they are not of the same kind. There are read-only DVDs which are mostly the pre-recorded movies or software DVDs that we buy from the market. The data on these discs is write protected, that is you can neither erase nor add any more data to the disc.
These discs can either be played on computer through a DVD-ROM or DVD- writer or the movie DVDs can be run through DVD players that need no computer attachment. It is easier to play CD on DVD-ROM or player, but DVD cannot be played through a simple CD-ROM.
The next is DVD-R or writeable DVD. This has the provision to record the data using a DVD- writer and this is one time process. After the data is recorded on the blank disc, it cannot be erased and then you use it as DVD-ROM. This is good for single use data recording.
However, every time it is not feasible to go on writing DVDs and storing a whole lot of them to access your desired data. Sometimes, it makes sense to have a device which has the provision of recording time and over again, by replacing the previously written data. Thus, for such purpose DVD-RW or rewriteable discs are useful. You can write on these discs and erase the data many times, hence making it more versatile for use. This is an ideal option when a person is on the move and needs to use the device at many places, collecting data from many machines and sources.
The world of DVDs
DVDs are very useful to store data externally and being a light and compact disc, it is easy to carry anywhere. Initially the DVDs were used to record videos and thus were known as “digital video disc”. Nonetheless, with changing times, the disc is being used to record audio files as well as software data, etc. The most popular brands of DVD makers are Philips, JVC, Sony, Toshiba, Pioneer and others.
To begin with, there were two optical disc storage formats and they were Multimedia Compact Disc (MMCD) and Super Density (SD) disc. However, there was difference of opinion between the major companies on the usage of the format. Finally, it was decided that the disc would be enabled with reading option from only one side in the dual- layered disc, instead having to flip it. Now Optical Storage Technology Association (OSTA) has assigned ISO-13346 as the common file structure known as Universal Disk Format to be used for DVDs.
CDs and DVDs replaced the usage of VHS tapes that were used for video recording in the earlier days. This was because the recording on DVD gives better video as well as audio quality. Besides this, the disc has a longer life span and is easy to possess. This encouraged the movie makers to make permanent discs of the movies and put them up for sale to earn better profits than giving them out for rentals. DVDs can be easily posted and can be mass produced and this makes it a more viable option for recording and data storing.
Advantages of using DVD
Digital Versatile Disc (DVD) is recorded using MPEG-2 file and compression format. This gives a higher resolution picture than MPEG-1. As far as audio quality is concerned, the DVD-Audio format delivers high reliability audio on DVD. The audio can be configured to play through many options, from mono output to 5.1 stereo surround sound.
Commercially produced DVDs of software, movies, etc are secured by an encrypted code (CSS) that prevents copying of the content. Nevertheless, with CSS-decrypting software nowadays it is easier to break the code and copy the content on your hard drive as well as remove the regional code bar etc.
Data on DVD can be stored for a long time without damage if certain storing norms are taken into consideration. The DVD has best working life if stored at lower temperatures of 18°C (64.4°F) or less and relative humidity of 40% or lower. The longevity of the data on disc also depends on the quality of the recording and media (the disc itself).
A world in your pocket
DVDs have revolutionized the concept of data storage to certain extent. It has given freedom of having easy access to your content, audio, video etc. Now no more blocking space on the hard drive or maintaining data on tapes, if you want the audio video content at your disposal anytime anyplace, all that you need is the playing device and your stuff is ready for you on an easily portable disc. The normal DVD is 12 cms in diameter and there is a mini DVD available that is only 8 cms in diameter. A normal single-sided single layer 8 cms DVD has a capacity of 1.36 GB as against 4.37 GB of the 12 cms variety. For enhanced viewing of videos and good quality audio it is best to store the content on a DVD.