Tech moves fast! Stay ahead of the curve with Techopedia!
Join nearly 200,000 subscribers who receive actionable tech insights from Techopedia.
A digital versatile disc (DVD) is an optical disc storage medium similar to a compact disc, but with enhanced data storage capacities as well as with higher quality of video and audio formats. Codeveloped by Sony, Panasonic, Philips and Toshiba in 1995, the DVD is widely used for video formats, audio formats as well software and computer files.
Digital versatile discs are also known as digital video discs.
A digital versatile disc has a large capacity, starting at 4.7 GB. They are written at a speed of 18-20x and have a video compression ratio of 40:1 with the help of MPEG-2 compression. The materials and manufacturing techniques used in the case of a digital versatile disc are same as that of CDs. The layers in the DVD are made by polycarbonate plastic. Digital versatile discs can be categorized in different ways based on their applications. If they are used for reading only and cannot be written, then they are classified as DVD-ROM. If the DVDs can be used to record any type of data, then they are called DVD-R. If the disc can be read, written and then erased and rewritten, it is called DVD-RW.
There are many advantages associated with the DVD format. Compared to a CD, the audio quality is superior thanks to DTS or Dolby Digital technology. The picture quality is also superior to CD and the DVD player is capable of taking one to a specific moment in the video or audio, unlike a CD player. Based on the user needs, the formats of the digital versatile disc can be altered. Again, digital versatile discs are capable of storing more data compared to CD. This is due to smaller size of the pits and bumps and high density of the tracks in the DVDs. A large amount of space is wasted in codes, to avoid errors in information in the case of CDs. Digital versatile discs are backward compatible as well.
One disadvantage of DVDs is the higher access time, which is mainly because of the higher amount of data and greater density.