disk or disc may refer to:

Data storage

Aluminum disc, a magnetic recording disc used mainly for early radio recordings

Blu-ray Disc, a high-density optical disc intended mainly for video storage

Compact Disc, a form of optical disc used mainly for audio data

Disc film, a still-photography film format

Disk storage, a general category of data storage mechanisms

DVD, a form of optical disc used mainly for video and other data

Enhanced Versatile Disc, an optical medium-based digital audio/video format under development (shortform EVD)

Floppy disk, a magnetic data storage device using a flexible disc

Hard disk drive, a non-volatile magnetic data storage device

HD DVD, a high-density optical disc intended mainly for video storage

Laserdisc, the first commercial optical disc storage medium

MiniDisc, a magneto-optical disc-based data storage device

Optical disc, a polycarbonate disc

RAM disk, a volatile solid state drive

Transcription disc, a gramophone record

A generic name for secondary storage in a computer

Science

Accretion disk, diffuse material in orbital motion around a central body such as a star or black hole

Death Inducing Signaling Complex, in biology, a multi-protein complex formed by members of the death receptor family of apoptosis-inducing cellular receptors

Debris disk, a ring shaped circumstellar disk of dust and debris in orbit around a star

DISC assessment, in psychology, a group of psychometric tests based on the work of William Moulton Marston

Disc (galaxy), a disc-shaped group of stars

Disk (mathematics), the region in a plane surrounded by a circle

Intervertebral disc, in biology, part of the spine of an animal

Protoplanetary disk, a rotating disc of dense gas surrounding a newly formed star, a form of accretion disc

Scattered disc, a distant region of the Solar System thinly populated by icy minor planets

Unit disk, a disc (mathematics) with radius one

Motoring

Disc brake, a device for slowing or stopping the rotation of a wheel

Disc parking, a parking regulation with free parking when using a parking disc (clock disc)

Tax disc, a Vehicle licence#United Kingdom receipt placed inside windscreen

Other uses

DİSK, the Confederation of Revolutionary Trade Unions of Turkey

Disc jockey, a person who selects and plays pre-recorded music for an audience

Flying disc, a throwing toy or Frisbee

DISK (student union), at Stockholm University