A gramophone record (phonograph record in American English) or vinyl record, commonly known as a "record", is an analog sound storage medium in the form of a flat polyvinyl chloride (previously shellac) disc with an inscribed, modulated spiral groove. The groove usually starts near the periphery and ends near the center of the disc. Phonograph records are generally described by their diameter in inches (12", 10", 7"), the rotational speed in rpm at which they are played (16 2⁄3, 33 1⁄3, 45, 78), and their time capacity resulting from a combination of those parameters (LP – long playing 33 1⁄3 rpm, SP – 78 rpm single, EP – 12-inch single or extended play, 33 or 45 rpm); their reproductive quality or level of fidelity (high-fidelity, orthophonic, full-range, etc.), and the number of audio channels provided (mono, stereo, quad, etc.).
The phonograph disc record was the primary medium used for music reproduction until late in the 20th century, replacing the phonograph cylinder record, with which it had co-existed, by the 1920s. By the late 1980s, digital media, in the form of the compact disc, had gained a larger market share, and the vinyl record left the mainstream in 1991. After its fall, records continued to be manufactured and sold, and have been especially used by disc jockeys and many audiophiles for various types of music. The phonograph record has made a niche resurgence in the early 21st century – 9.2 million records were sold in the U.S. in 2014, a 260% increase since 2009. Likewise, in the UK sales have increased five-fold from 2009 to 2014.