An optical disc is a flat, usually disc-shaped object that stores information in the form of physical variations on its surface that can be read with the aid of a beam of light. Optical discs can be reflective, where the light source and detector are on the same side of the disc, or transmissive, where light shines through the disc to be detected on the other side.
A DVD player is a device that plays DVDs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. Some DVD players will also play audio CDs. DVD players are connected to a television to watch the DVD content, which could be a movie, a recorded TV show, or other content.
Videodisc is a general term for a laser- or stylus-readable random-access disc that contains both audio and analog video signals recorded in an analog form. Typically, it is a reference to any such media that predates the mainstream popularity of the DVD format. The first mainstream official Videodisc was the Television Electronic Disc (TED) Videodisc, and the newest is the 4K Ultra HD Blu-Ray Disc. As of September 2023, the active video disc formats are Blu-ray Disc, DVD, and in other regions because of the price difference from DVD, Video CD (VCD) and SVCD.
In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, but recent drives can both read and record, also called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives.
DVD-RAM is a DVD-based disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998.
A format war is a competition between similar but mutually incompatible technical standards that compete for the same market, such as for data storage devices and recording formats for electronic media. It is often characterized by political and financial influence on content publishers by the developers of the technologies. Developing companies may be characterized as engaging in a format war if they actively oppose or avoid interoperable open-industry technical standards in favor of their own.
Optical disc packaging is the packaging that accompanies CDs, DVDs, and other formats of optical discs. Most packaging is rigid or semi-rigid and designed to protect the media from scratches and other types of exposure damage.
The Capacitance Electronic Disc (CED) is an analog video disc playback system developed by Radio Corporation of America (RCA), in which video and audio could be played back on a TV set using a special stylus and high-density groove system similar to phonograph records.
A disk enclosure is a specialized casing designed to hold and power hard disk drives or solid state drives while providing a mechanism to allow them to communicate to one or more separate computers.
A DVD recorder is an optical disc recorder that uses optical disc recording technologies to digitally record analog or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in television studios or home theater systems.
Professional Disc (PFD) is a digital recording optical disc format introduced by Sony in 2003 primarily for XDCAM, its tapeless camcorder system. It was one of the first optical formats to utilize a blue laser, which allowed for a higher density of data to be stored on optical media compared to infrared laser technology used in the CD and red laser technology used in the DVD format.
Optical disc authoring requires a number of different optical disc recorder technologies working in tandem, from the optical disc media to the firmware to the control electronics of the optical disc drive.
A compressed audio optical disc, MP3 CD, or MP3 CD-ROM or MP3 DVD is an optical disc that contains digital audio in the MP3 file format. Discs are written in the "Yellow Book" standard data format, as opposed to the Red Book standard audio format.
This article compares the technical specifications of multiple high-definition formats, including HD DVD and Blu-ray Disc; two mutually incompatible, high-definition optical disc formats that, beginning in 2006, attempted to improve upon and eventually replace the DVD standard. The two formats remained in a format war until February 19, 2008, when Toshiba, HD DVD's creator, announced plans to cease development, manufacturing and marketing of HD DVD players and recorders.
The DVD is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kind of digital data and has been widely used to store video programs, software and other computer files. DVDs offer significantly higher storage capacity than compact discs (CD) while having the same dimensions. A standard single-layer DVD can store up to 4.7 GB of data, a dual-layer DVD up to 8.5 GB. Variants can store up to a maximum of 17.08 GB.
Blu-ray is a digital optical disc data storage format designed to supersede the DVD format. It was invented and developed in 2005 and released worldwide on June 20, 2006, capable of storing several hours of high-definition video. The main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, PlayStation 5, Xbox One, and Xbox Series X. The name refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs.
HD DVD is an obsolete high-density optical disc format for storing data and playback of high-definition video. Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format, but lost to Blu-ray, supported by Sony and others.
As of 2021, multiple consumer-oriented, optical-disk media formats are or were available:
The preservation of optical media is essential because it is a resource in libraries, and stores audio, video, and computer data to be accessed by patrons. While optical discs are generally more reliable and durable than older media types, environmental conditions and/or poor handling can result in lost information.
This glossary of computer hardware terms is a list of definitions of terms and concepts related to computer hardware, i.e. the physical and structural components of computers, architectural issues, and peripheral devices.
