Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. The format was originally developed to store and play only sound recordings (CD-DA) but was later adapted for storage of data (CD-ROM). Several other formats were further derived from these, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Disc (VCD), Super Video Compact Disc (SVCD), Photo CD, PictureCD, CD-i, and Enhanced Music CD. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan.
CD-R is a digital optical disc storage format. A CD-R disc is a compact disc that can be written once and read arbitrarily many times.
Disc golf is a flying disc sport in which players throw a disc at a target; it is played using rules similar to golf. It is often played on a course of 9 or 18 holes. Players complete a hole by throwing a disc from a tee area toward a target, throwing again from the landing position of the disc until the target is reached. Usually, the number of throws a player uses to reach each target are tallied, and players seek to complete each hole, and the course, in the lowest number of total throws.
A frisbee is a gliding toy or sporting item that is generally made of injection molded plastic and roughly 8 to 10 inches in diameter with a pronounced lip. It is used recreationally and competitively for throwing and catching, as in flying disc games. The shape of the disc is an airfoil in cross-section which allows it to fly by generating lift as it moves through the air. Spinning the disc imparts a stabilizing gyroscopic force, allowing it to be both aimed with accuracy and thrown for distance.
Ultimate, originally known as ultimate frisbee, is a non-contact team sport played with a flying disc (frisbee). Ultimate was developed in 1968 by a group of students at Columbia High School in Maplewood, New Jersey. Although Ultimate resembles many traditional sports in its athletic requirements, it is unlike most sports due to its focus on self-officiating, even at the highest levels of competition. The term frisbee, often used to generically describe all flying discs, is a registered trademark of the Wham-O toy company, and thus the sport is not formally called "Ultimate frisbee", though this name is still in common casual use. Points are scored by passing the disc to a teammate in the opposing end zone. Other basic rules are that players must not take steps while holding the disc, and interceptions, incomplete passes, and passes out of bounds are turnovers. Rain, wind, or occasionally other adversities can make for a testing match with rapid turnovers, heightening the pressure of play.
In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc which encodes binary data (bits) in the form of pits and lands on a special material on one of its flat surfaces. The encoding material sits atop a thicker substrate which makes up the bulk of the disc and forms a dust defocusing layer. The encoding pattern follows a continuous, spiral path covering the entire disc surface and extending from the innermost track to the outermost track. The data is stored on the disc with a laser or stamping machine, and can be accessed when the data path is illuminated with a laser diode in an optical disc drive which spins the disc at speeds of about 200 to 4,000 RPM or more, depending on the drive type, disc format, and the distance of the read head from the center of the disc. Most optical discs exhibit a characteristic iridescence as a result of the diffraction grating formed by its grooves. This side of the disc contains the actual data and is typically coated with a transparent material, usually lacquer. The reverse side of an optical disc usually has a printed label, sometimes made of paper but often printed or stamped onto the disc itself. Unlike the 31⁄2-inch floppy disk, most optical discs do not have an integrated protective casing and are therefore susceptible to data transfer problems due to scratches, fingerprints, and other environmental problems.
MiniDisc (MD) is a magneto-optical disc-based data storage format offering a capacity of 60, 74 minutes and, later, 80 minutes, of digitized audio or 1 gigabyte of Hi-MD data. Sony brand audio players were on the market in September 1992.
A disc brake is a type of brake that uses calipers to squeeze pairs of pads against a disc or "rotor" to create friction. This action slows the rotation of a shaft, such as a vehicle axle, either to reduce its rotational speed or to hold it stationary. The energy of motion is converted into waste heat which must be dispersed.
In the music industry, a single is a type of release, typically a song recording of fewer tracks than an LP record or an album. This can be released for sale to the public in a variety of different formats. In most cases, a single is a song that is released separately from an album, although it usually also appears on an album. Typically, these are the songs from albums that are released separately for promotional uses such as digital download or commercial radio airplay and are expected to be the most popular. In other cases a recording released as a single may not appear on an album.
An extended play record, often referred to as an EP, is a musical recording that contains more tracks than a single, but is usually unqualified as an album or LP. Contemporary EPs generally contain a minimum of three tracks and maximum of six tracks, and are considered "less expensive and time-consuming" for an artist to produce than an album. An EP originally referred to specific types of vinyl records other than 78 rpm standard play (SP) and LP, but it is now applied to mid-length CDs and downloads as well.
A phonograph record, often simply record, is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts near the periphery and ends near the center of the disc. At first, the discs were commonly made from shellac; starting in the 1940s polyvinyl chloride became common. Since then, gradually, records made of any material began to be called vinyl records, or simply vinyl.
Desert Island Discs is a radio programme broadcast on BBC Radio 4. It was first broadcast on the BBC Forces Programme on 29 January 1942.
LaserDisc is a home video format and the first commercial optical disc storage medium, initially licensed, sold and marketed as MCA DiscoVision in the United States in 1978.
In computing, an optical disc drive (ODD) 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. Optical disc drives that are no longer in production include CD-ROM drive, CD writer drive, combo (CD-RW/DVD-ROM) drive, and DVD writer drive supporting certain recordable and rewritable DVD formats. As of 2015, DVD writer drive supporting all existing recordable and rewritable DVD formats is the most common for desktop PCs and laptops. There are also the DVD-ROM drive, BD-ROM drive, Blu-ray Disc combo (BD-ROM/DVD±RW/CD-RW) drive, and Blu-ray Disc writer drive.
DVDregion codes are a digital rights management technique designed to allow rights holders to control the international distribution of a DVD release, including its content, release date, and price, all according to the appropriate region.
Spinal disc herniation is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for disc herniation is MRI, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by core strength and an awareness of body mechanics including posture.
The LP is an analog sound storage medium, a vinyl record format characterized by a speed of 33 1⁄3 rpm, a 12- or 10-inch diameter, and use of the "microgroove" groove specification. Introduced by Columbia in 1948, it was soon adopted as a new standard by the entire record industry. Apart from a few relatively minor refinements and the important later addition of stereophonic sound, it has remained the standard format for vinyl albums.
DVD is a digital optical disc storage format invented and developed in 1995. The medium can store any kind of digital data and is widely used for software and other computer files as well as video programs watched using DVD players. DVDs offer higher storage capacity than compact discs while having the same dimensions.
Blu-ray or Blu-ray Disc (BD) is a digital optical disc data storage format. It was designed to supersede the DVD format, and is capable of storing several hours of video in high-definition and ultra high-definition resolution (2160p). 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, and Xbox One. The name "Blu-ray" 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.
A CD-ROM is a pre-pressed optical compact disc that contains data. Computers can read—but not write to or erase—CD-ROMs, i.e. it is a type of read-only memory.
