|Media type||Optical disc|
|Capacity||~4. 7 GB (single-sided single-layer), ~8. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer 54 GB (single-sided double-layer)|
|Read mechanism||650 nm laser, 10. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer 5 Mbit/s (1×)|
|Write mechanism||10. In telecommunications Bit rate or Data transfer rate is the average number of Bits characters or blocks per unit time passing between equipment in a data transmission 5 Mbit/s (1×)|
|Usage||Data storage, video, audio, games|
DVD (also known as "Digital Versatile Disc" or "Digital Video Disc" - see Etymology) is a popular optical disc storage media format. In telecommunications Bit rate or Data transfer rate is the average number of Bits characters or blocks per unit time passing between equipment in a data transmission DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is A data storage device is a device for recording (storing information (data Its main uses are video and data storage. Video is the technology of electronically capturing, Recording, processing storing transmitting and reconstructing a sequence of Still images Debt AIDS Trade in Africa (or DATA) is a Multinational non-government organization founded in January 2002 in London by U2 's Most DVDs are of the same dimensions as compact discs (CDs) but store more than six times as much data. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio
Variations of the term DVD often describe the way data is stored on the discs: DVD-ROM has data which can only be read and not written, DVD-R and DVD+R can be written once and then function as a DVD-ROM, and DVD-RAM, DVD-RW, or DVD+RW hold data that can be erased and thus re-written multiple times. DVD-R is a DVD recordable format A DVD-R typically has a storage capacity of 4 A DVD+R is a once-writable Optical disc with 47 GB (4377 GiB) of storage capacity (more precisely 2295104 sectors of 2048 Bytes DVD-RAM ( DVD – Random Access Memory) is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate A DVD-RW disc is a rewritable Optical disc with equal storage capacity to a DVD-R, typically 4 DVD+RW is the name of a standard for Optical discs one of several types of DVD, which hold up to about 4 The wavelength used by standard DVD lasers is 650 nm, and thus has a red color. Red is any of a number of similar Colors evoked by light consisting predominantly of the longest wavelengths of Light discernible by the human eye in the wavelength
DVD-Video and DVD-Audio discs respectively refer to properly formatted and structured video and audio content. DVD-Video is a consumer video format used to store digital video on DVD (DVD-ROM discs and is currently the dominant form of consumer video formats in the United DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering very High-fidelity audio content on a DVD. Other types of DVDs, including those with video content, may be referred to as DVD-Data discs. As next generation High definition optical formats also use a disc identical in some aspects yet more advanced than a DVD, such as Blu-ray Disc, the original DVD is often given the retronym SD DVD (for standard definition). A retronym is a type of Neologism coined for an old object or concept whose original name has come to be used for something else is no longer unique or is otherwise inappropriate 
|Optical media types|
In 1993, two high-density optical storage formats were being developed; one was the MultiMedia Compact Disc (MMCD), backed by Philips and Sony, and the other was the Super Density (SD) disc, supported by Toshiba, Time Warner, Matsushita Electric, Hitachi, Mitsubishi Electric, Pioneer, Thomson, and JVC. Optical disc authoring, including DVD and Blu-ray Disc authoring (often referred to colloquially but improperly as burning) is the process of assembling In Computing, an optical disc drive ( ODD) is a Disk drive that uses Laser light or electromagnetic waves near the Light spectrum Optical disc authoring, including DVD and Blu-ray Disc authoring (often referred to colloquially but improperly as burning) is the process of assembling Optical disc authoring software is Computer software for authoring optical discs including CD-ROMs and DVDs They are also known by synonyms Optical disc authoring requires a number of different technologies working in tandem from the media to the firmware to the control electronics of the drive. In Optical disc authoring, there are multiple modes for recording including Disc-At-Once, Track-At-Once, and Session-At-Once. Packet writing is an Optical disc recording technology used to allow write-once and rewritable CD and DVD media to be used in a similar manner to a The Laserdisc (LD is an obsolete Home video disc format and was the first commercial Optical disc storage medium Video Single Disc (abbreviated as VSD was a disc-based format that carried the same analog video information as a Laserdisc, but on a 12-centimetre (4 A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio Red Book is the standard for audio CDs ( Compact Disc Digital Audio system or CDDA) The DTS-CD, DTS Audio CD or 51 Music Disc (official name is an audio Compact Disc that contains music in Surround sound format Super Audio CD ( SACD) is a read-only optical audio disc format that can provide higher fidelity digital audio reproduction than the Red Photo CD is a system designed by Kodak for digitizing and storing photos in a CD A CD-R ( C ompact D isc- R ecordable is a variation of the Compact Disc invented by Philips and Sony. CD-ROM (an initialism of "Compact Disc Read-Only Memory " is a pre-pressed Compact Disc that contains data accessible to but not writable Compact Disc ReWritable (CD-RW is a rewritable Optical disc format This article is about 'CD Video' a hybrid analog/digital format Super Video CD ( Super Video Compact Disc or SVCD) is a Digital format for storing Video on standard Compact discs SVCD was intended A CD+G (also known as CD+Graphics) is a special audio Compact disc that contains Graphics Data in addition to the audio data CD-Text is an extension of the Red Book Compact Disc specifications standard for Audio CDs It allows for storage of additional information (e CD-ROM XA is an extension of the Yellow Book Mode 2 standard for CD-ROMs that combines compressed audio visual and computer data allowing all to be accessed CD-i or Compact Disc Interactive is the name of an interactive multimedia CD player developed and marketed by Royal Philips Electronics N A MiniDisc ( MD) is a Magneto-optical disc-based Data storage device initially intended for storage of up to 80 minutes of digitized audio In January 2004 Sony announced the Hi-MD media storage format as a further development of the MiniDisc-Format. DVD-R is a DVD recordable format A DVD-R typically has a storage capacity of 4 A DVD+R is a once-writable Optical disc with 47 GB (4377 GiB) of storage capacity (more precisely 2295104 sectors of 2048 Bytes DVD-R DL (DL stands for Dual Layer) also called DVD-R9, is a derivative of the DVD-R format standard DVD+R DL (DL stands for Double Layer) also called DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance. A DVD-RW disc is a rewritable Optical disc with equal storage capacity to a DVD-R, typically 4 DVD+RW is the name of a standard for Optical discs one of several types of DVD, which hold up to about 4 DVD-RW DL is a rewritable Optical disc standard with storage capacity of 8 A DVD+RW DL is a rewritable Optical disc with storage capacity of 8 DVD-RAM ( DVD – Random Access Memory) is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD-Ds, also referred to as disposable DVDs are a type of digital video disc that is designed to be used for a maximum 48 hours after the containing package is opened Ultra Density Optical ( UDO) is an Optical disc format designed for high-density storage of high-definition video and The Universal Media Disc ( UMD) is an Optical disc medium developed by Sony for use on the PlayStation Portable. not insert the publicly disclosed HD DVD key into this article for the time being not insert the publicly disclosed HD DVD key into this article for the time being not insert the publicly disclosed HD DVD key into this article for the time being not insert the publicly disclosed HD DVD key into this article for the time being not insert the publicly disclosed HD DVD key into this article for the time being Blu-ray Disc recordable (or BD-R) refers to two Optical disc formats that can be recorded with an Optical disc recorder. For the series of US government publications on Computer security standards see Rainbow Series. ISO 9660 a standard published by the International Organization for Standardization (ISO defines a File system for CD-ROM media Joliet is the name of an extension to the ISO 9660 File system. The Rock Ridge Interchange Protocol (RRIP IEEE P1282 is an extension to the ISO 9660 volume format which adds POSIX File system semantics The El Torito Bootable CD Specification is an extension to the ISO 9660 CD-ROM specification The primary file system for Apple Macintosh computers is HFS (or HFS+ Mount Rainier ( MRW) is a format for writable Optical discs which provides the Packet writing and defect management Although research into Optical data storage has been ongoing for many decades the first popular system was the Compact Disc, introduced in 1982, adapted to data Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with ( is a multinational conglomerate manufacturing company headquartered in Tokyo, Japan. Time Warner Inc ( is the world's largest media and entertainment conglomerate, headquartered in New York City. () is a Multinational corporation specializing in high-technology and services headquartered in Marunouchi Itchome Chiyoda, Tokyo, Japan. ( is a Japanese company based in the Tokyo Building in Tokyo, manufactures electric and architectural equipment as well as a major worldwide producer of ( is a Multinational Corporation that specializes in digital entertainment products based in Tokyo, Japan. Thomson SA (,) formerly known as Thomson Multimedia is an international provider of solutions for the creation management delivery and access of video for the ( usually referred to as JVC, is an International consumer and professional electronics Corporation based in Yokohama, Japan which was founded
Representatives of the SD camp approached IBM, asking for advice on the file system to use for their disk as well as looking for support for their format for storing computer data. International Business Machines Corporation abbreviated IBM and nicknamed "Big Blue", is a multinational Computer Technology A researcher from IBM's Almaden Research Center received that request, and also learned of the MMCD development project. Wary of being caught in a repeat of the costly videotape format war between VHS and Betamax of the 1980s, he convened a group of computer industry experts (including representatives from Apple, Microsoft, Sun, Dell, and many others); this group was referred to as the Technical Working Group, or TWG. ---- Betamax is a home Videocassette tape recording format developed by Sony, and released on May 10, 1975. Apple Inc, ( formerly Apple Computer Inc, is an American Multinational corporation with a focus on designing and manufacturing Consumer electronics Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer Sun Microsystems Inc ( is a multinational vendor of Computers computer components Computer software, and Information technology services The multinational technology company Dell Inc develops manufactures sells and supports Personal computers and other computer-related products The TWG voted to boycott both formats unless the two camps agreed on a single, converged standard. Lou Gerstner, President of IBM, was recruited to apply pressure on the executives of the warring factions. Louis V Gerstner Jr KBE (born March 1, 1942 in Mineola New York) was chairman of the board and chief executive officer of Eventually, the computer companies won the day, and a single format, now called DVD, was agreed upon. The TWG also collaborated with the Optical Storage Technology Association (OSTA) on the use of their implementation of the ISO-13346 file system, known as Universal Disk Format (UDF), for use on the new DVDs. The Optical Storage Technology Association (OSTA is an international Trade association which promotes the use of recordable optical technologies and products and most The Universal Disk Format ( UDF) is a format specification of a File system for storing files on optical media
Philips and Sony abandoned their MultiMedia Compact Disc and agreed upon a spec mostly similar to Toshiba and Matsushita's Super Density Disc except for the dual-layer option (MMCD was single-sided and optionally dual-layer whereas SD was single-layer but optionally double-sided) and EFMPlus modulation. Eight-to-Fourteen Modulation ( EFM) is a data encoding technique used by CDs and pre- Hi-MD MiniDiscs EFM and EFMPlus were both invented EFMPlus was chosen as it has a great resilience against disc damage such as scratches and fingerprints. EFMPlus, created by Kees Immink, who also designed EFM, is 6% less efficient than the modulation technique originally used by Toshiba, which resulted in a capacity of 4. Kornelis Antonie (Kees Schouhamer Immink (born 18 December, 1946 in Rotterdam) is a Dutch scientist inventor and entrepreneur who pioneered Eight-to-Fourteen Modulation ( EFM) is a data encoding technique used by CDs and pre- Hi-MD MiniDiscs EFM and EFMPlus were both invented 7 GB as opposed to the original 5 GB. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer The result was the DVD specification, finalized for the DVD movie player and DVD-ROM computer applications in December 1995.  In May 1997, the DVD Consortium was replaced by the DVD Forum, which is open to all other companies. The DVD Forum is an international organization composed of hardware software media and content companies that use and develop the DVD and HD DVD formats The DVD Forum is an international organization composed of hardware software media and content companies that use and develop the DVD and HD DVD formats
"DVD" was originally used as an initialism for the unofficial term "digital video disk". Acronyms, initialisms, and alphabetisms are Abbreviations that are formed using the initial components in a phrase or name  It was reported in 1995, at the time of the specification finalization, that the letters officially stood for "digital versatile disc" (due to non-video applications), However, the text of the press release announcing the specification finalization only refers to the technology as "DVD", making no mention of what (if anything) the letters stood for.  A newsgroup FAQ written by Jim Taylor (a prominent figure in the industry) claims that four years later, in 1999, the DVD Forum stated that the format name was simply the three letters "DVD" and did not stand for anything. FAQ is an Acronym for " Frequently Asked Question(s " 
The official DVD specification documents have never defined DVD. Usage in the present day varies, with "DVD", "Digital Video Disc", and "Digital Versatile Disc" being the most common.
The DVD Forum website has a section called "DVD Primer" in which the answer to the question, "What does DVD mean?" reads, "The keyword is 'versatile. The DVD Forum is an international organization composed of hardware software media and content companies that use and develop the DVD and HD DVD formats ' Digital Versatile discs provide superb video, audio and data storage and access -- all on one disc. "
|DVD-1||SS SL||1||1||8||1. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer A gibibyte (a contraction of gi ga bi nary byte) is a unit of Information or Computer storage, abbreviated GiB. 46||1. 36|
|DVD-2||SS DL||1||2||8||2. 66||2. 47|
|DVD-3||DS SL||2||2||8||2. 92||2. 72|
|DVD-4||DS DL||2||4||8||5. 32||4. 95|
|DVD-5||SS SL||1||1||12||4. 70||4. 37|
|DVD-9||SS DL||1||2||12||8. 54||7. 95|
|DVD-10||DS SL||2||2||12||9. 40||8. 74|
|DVD-14||DS DL/SL||2||3||12||13. 24||12. 32|
|DVD-18||DS DL||2||4||12||17. 08||15. 90|
The basic types of DVD are referred to by a rough approximation of their capacity in gigabytes.
The 12 cm type is a standard DVD, and the 8 cm variety is known as a mini-DVD. There are two types of MiniDVDs. 80 mm DVD, which are smaller versions of the 120 mm DVD cDVD, which are standard These are the same sizes as a standard CD and a mini-CD, respectively. Not to be confused with MiniDisc. Mini CD s or "Pocket" CDs are Compact discs with a smaller Form factor
Note: Like with hard disk drives in the DVD realm gigabyte and the symbol GB are usually used in the SI sense, i. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer e. 109 (or 1,000,000,000) bytes. For distinction, gibibyte with symbol GiB is used, i. A gibibyte (a contraction of gi ga bi nary byte) is a unit of Information or Computer storage, abbreviated GiB. e. 230 (or 1,073,741,824) bytes. Most computer operating systems display file sizes in gibibytes, mebibytes and kibibytes labeled as gigabyte, megabyte and kilobyte respectively. A mebibyte (a contraction of me ga bi nary byte) is a unit of Information or Computer storage, abbreviated MiB. A kibibyte (a contraction of ki lo bi nary byte) is a unit of Information or Computer storage, established by the International
Each DVD sector contains 2418 bytes of data, 2048 bytes of which are user data.
There is a small difference in storage space between ‘+’ and ‘-’ formats:
|DVD−R SL||2,298,496||4,707,319,808||4. 71||4. 384|
|DVD+R SL||2,295,104||4,700,372,992||4. 70||4. 378|
|DVD−R DL||4,171,712||8,543,666,176||8. 54||7. 957|
|DVD+R DL||4,173,824||8,547,991,552||8. 55||7. 961|
DVD uses 650nm wavelength laser diode light as opposed to 780 nm for CD or 405 nm for HD-DVD or Blu-ray Disc. A laser diode is a Laser where the active medium is a Semiconductor similar to that found in a Light-emitting diode. This permits a smaller pit to be etched on the media surface (1. 32 µm for DVD versus 2. 11 µm for CD) compared to CDs.
Writing speeds for DVD were 1×, that is 1350 kB/s (1318 KiB/s), in the first drives and media models. A kilobyte (derived from the SI prefix Kilo -, meaning 1000 is a unit of Information or Computer storage equal to either 1024 In computing binary prefixes are names or associated symbols that can precede a unit of measure (such as a Byte) to indicate multiplication by a power of two More recent models at 18× or 20× have 18 or 20 times that speed. Note that for CD drives, 1× means 153. 6 Kb/s (150 KiB/s), 9 times slower. 
|Drive speed||Data rate||Write time (min)|
|1×||10. 55||1. 35||61||107|
|2×||21. 09||2. 70||30||54|
|2. 6×||27. 43||3. 51||24||42|
|4×||42. 19||5. 40||15||27|
|6×||63. 30||8. 10||11||18|
|8×||84. 38||10. 80||8||14|
|16×||168. 75||21. 60||4||7|
HP initially developed recordable DVD media from the need to store data for back-up and transport. DVD recordable and DVD rewritable refer to DVD Optical disc formats that can be recorded (written "burned" either write once
DVD recordables are now also used for consumer audio and video recording. Three formats were developed: DVD-R/RW (minus/dash), DVD+R/RW (plus), DVD-RAM. DVD-R is a DVD recordable format A DVD-R typically has a storage capacity of 4 A DVD-RW disc is a rewritable Optical disc with equal storage capacity to a DVD-R, typically 4 A DVD+R is a once-writable Optical disc with 47 GB (4377 GiB) of storage capacity (more precisely 2295104 sectors of 2048 Bytes DVD+RW is the name of a standard for Optical discs one of several types of DVD, which hold up to about 4 DVD-RAM ( DVD – Random Access Memory) is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate
Dual Layer recording allows DVD-R and DVD+R discs to store significantly more data, up to 8. DVD-R is a DVD recordable format A DVD-R typically has a storage capacity of 4 A DVD+R is a once-writable Optical disc with 47 GB (4377 GiB) of storage capacity (more precisely 2295104 sectors of 2048 Bytes 5 gigabytes per side, per disc, compared with 4. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer 7 gigabytes for single-layer discs. DVD-R DL was developed for the DVD Forum by Pioneer Corporation, DVD+R DL was developed for the DVD+RW Alliance by Philips and Mitsubishi Kagaku Media (MKM). DVD-R DL (DL stands for Dual Layer) also called DVD-R9, is a derivative of the DVD-R format standard ( is a Multinational Corporation that specializes in digital entertainment products based in Tokyo, Japan. DVD+R DL (DL stands for Double Layer) also called DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance. Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc. 
A Dual Layer disc differs from its usual DVD counterpart by employing a second physical layer within the disc itself. The drive with Dual Layer capability accesses the second layer by shining the laser through the first semi-transparent layer. The layer change can exhibit a noticeable pause in some DVD players, up to several seconds.  This caused more than a few viewers to worry that their dual layer discs were damaged or defective, with the end result that studios began listing a standard message explaining the dual layer pausing effect on all dual layer disc packaging.
DVD recordable discs supporting this technology are backward compatible with some existing DVD players and DVD-ROM drives.  Many current DVD recorders support dual-layer technology, and the price is now comparable to that of single-layer drives, though the blank media remains more expensive. The recording speeds reached by dual-layer media are still well below those of single-layer media.
There are two modes for dual layer orientation. With parallel track path (PTP), used on DVD-ROM, both layers start at the inside diameter (ID) and end at the outside diameter (OD) with the lead-out. With opposite track path (OTP), used on DVD-Video, the lower layer starts at the ID and the upper layer starts at the OD, where the other layer ends, they share one lead-in and one lead-out. 
DVD-Video is a standard for storing video content on DVD media. DVD-Video is a consumer video format used to store digital video on DVD (DVD-ROM discs and is currently the dominant form of consumer video formats in the United In the U. S. , mass retailer sales of DVD-Video titles and players began in late 1997.  By June 2003, weekly DVD-Video rentals began out-numbering weekly VHS cassette rentals, reflecting the rapid adoption rate of the technology in the U. S. marketplace.  Currently DVD-Video is the dominant form of home video distribution worldwide.
Though many resolutions and formats are supported, most consumer DVD-Video discs use either 4:3 or anamorphic 16:9 aspect ratio MPEG-2 video, stored at a resolution of 720×480 (NTSC) or 720×576 (PAL) at 29. Anamorphic widescreen is a videographic technique utilising rectangular (wide pixels to store a Widescreen image to standard 43 aspect ratio. The aspect ratio of a Shape is the ratio of its longer Dimension to its shorter dimension MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information" NTSC ( National Television System Committee) is the Analog television system used in the United States, Canada, Japan, Mexico PAL, short for Phase Alternating Line, is a colour -encoding system used in Broadcast television systems in large parts of the world 97 or 25 FPS. Frame rate, or frame frequency, is the measurement of the Frequency (rate at which an imaging device produces unique consecutive images called frames The Audio is commonly stored using the Dolby Digital (AC-3) or Digital Theater System (DTS) formats, ranging from 16-bits/48 kHz to 24-bits/96 kHz format with monaural to 7. Dolby Digital is the marketing name for a series of lossy audio compression technologies developed by Dolby DTS (also known as Digital Theater Systems) owned by DTS Inc ( is a multi-channel digital Surround sound format used for both commercial/theatrical Monaural (often shortened to mono) sound reproduction is single-channel 1 channel "Surround Sound" presentation, and/or MPEG-1 Layer 2. 51, Multichannel audio, Multichannel music Surround 3D Surround 5 MPEG-1 was an early Standard for Lossy compression of Video and audio. Although the specifications for video and audio requirements vary by global region and television system, many DVD players support all possible formats. DVD-Video also supports features like menus, selectable subtitles, multiple camera angles, and multiple audio tracks.
DVD-Audio is a format for delivering high-fidelity audio content on a DVD. DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering very High-fidelity audio content on a DVD. It offers many channel configuration options (from mono to 5. Monaural (often shortened to mono) sound reproduction is single-channel 1 surround sound) at various sampling frequencies (up to 24-bits/192 kHz versus CDDAs 16-bits/44. 51, Multichannel audio, Multichannel music Surround 3D Surround 5 1 kHz). Compared with the CD format, the much higher capacity DVD format enables the inclusion of considerably more music (with respect to total running time and quantity of songs) and/or far higher audio quality (reflected by higher sampling rates and greater bit-depth, and/or additional channels for spatial sound reproduction). Sampling theorem The Nyquist–Shannon sampling theorem states that perfect reconstruction Color depth. or bit depth, is a Computer graphics term describing the number of Bits used to represent the Color of a single Pixel 3D audio effects are a group of Sound effects that attempt to widen the stereo image produced by two Loudspeakers or stereo headphones or to create the illusion
Despite DVD-Audio's superior technical specifications, there is debate as to whether the resulting audio enhancements are distinguishable in typical listening environments. DVD-Audio currently forms a niche market, probably due to the very sort of format war with rival standard SACD that DVD-Video avoided. Super Audio CD ( SACD) is a read-only optical audio disc format that can provide higher fidelity digital audio reproduction than the Red
DVD-Audio discs employ a robust copy prevention mechanism, called Content Protection for Prerecorded Media (CPPM) developed by the 4C group (IBM, Intel, Matsushita, and Toshiba). Content Protection for Recordable Media and Pre-Recorded Media ( CPRM/CPPM) is a mechanism for controlling the copying moving and deletion of digital media on a host device Copy protection, also known as content protection, copy prevention, or copy restriction, is a technology for preventing the unauthorised reproduction Content Protection for Recordable Media and Pre-Recorded Media ( CPRM/CPPM) is a mechanism for controlling the copying moving and deletion of digital media on a host device
To date, CPPM has not been "broken" in the sense that DVD-Video's CSS has been broken, but ways to circumvent it have been developed. Content Scramble System ( CSS) is a Digital Rights Management (DRM scheme used on almost all commercially produced DVD -Video discs  By modifying commercial DVD(-Audio) playback software to write the decrypted and decoded audio streams to the hard disk, users can, essentially, extract content from DVD-Audio discs much in the same way they can from DVD-Video discs.
In 2006, a new format called Blu-ray Disc (BD), designed by Sony, Philips, and Panasonic, was released as the successor to DVD. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc. Another format, HD DVD, competed unsuccessfully with this format in a format war from 2006 to 2008. not insert the publicly disclosed HD DVD key into this article for the time being A format war describes competition between mutually incompatible proprietary formats typically for Data storage devices and Recording formats for Electronic
However, unlike previous format changes (i. e. vinyl records to compact disc, VHS videotape to DVD), there is no immediate indication that production of the standard DVD will gradually wind down, as they still dominate with around 97% of video sales.  Consumers have been slow to adopt Blu-ray, partly due to the initial cost, with Blu-ray players selling for $400 USD or more, while titles retail for $30 USD or higher, plus one requires a high-definition TV and appropriate connection cords to take advantage of it. Some analysts suggest that the biggest obstacle to replacing DVD is due to its installed base; a large majority of consumers are satisfied with DVDs.  The DVD had succeeded because it offered a compelling alternative to VHS. In addition, both HD DVD and Blu-ray players are designed to be backwards compatible, allowing older DVDs to be played since the media are physically identical; this differed from the change from vinyl to CD and from tape to DVD which involved a complete change in physical medium. In Technology, especially Computing (irrespective of platform a product is said to be backward compatible when it is able to take the place of an older product This situation can be best compared to the changeover from 78 rpm vinyl recordings to 45 rpm and 33 1/3 rpm recordings; since the medium used for the earlier format was virtually the same as the latter version (a disk on a turntable, played using a needle), phonographs continued to be built to play obsolete 78s for decades after the format was discontinued. A gramophone The phonograph, or gramophone, was the most common device for playing recorded Sound from the 1870s through the 1980s Manufacturers have announced standard DVD releases well into 2009, and the format remains the preferred one for the release of older television programs and films, with some programs such as Star Trek: The Original Series requiring reediting and replacement of certain elements such as special effects in order to be felt acceptable for high-definition viewing. Star Trek is a Science fiction Television series created by Gene Roddenberry that aired from September 8, 1966 through