''Disc'' and ''disk'' are both variants of the English word for objects of a generally thin and cylindrical geometry. The differences in spelling correspond both with regional differences and with different
senses of the word. For example, in the case of
flat, rotational data storage media the convention is that the spelling ''disk'' is used for
magnetic storage
Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetizable material to store data and is a form of non-volatile memory. The information is acc ...
(e.g.,
hard disk
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...
s) while ''disc'' is used for
optical storage (e.g.,
compact disc
The compact disc (CD) is a Digital media, digital optical disc data storage format co-developed by Philips and Sony to store and play digital audio recordings. It employs the Compact Disc Digital Audio (CD-DA) standard and was capable of hol ...
s, better known as CDs). When there is no clear convention, the spelling ''disk'' is more popular in
American English
American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...
, while the spelling ''disc'' is more popular in
British English
British English is the set of Variety (linguistics), varieties of the English language native to the United Kingdom, especially Great Britain. More narrowly, it can refer specifically to the English language in England, or, more broadly, to ...
.
Disk
The earlier word is ''disk'', which came into the
English language
English is a West Germanic language that developed in early medieval England and has since become a English as a lingua franca, global lingua franca. The namesake of the language is the Angles (tribe), Angles, one of the Germanic peoples th ...
in the middle of the 17th century. In the 19th century, ''disk'' became the conventional spelling for
audio recordings made on a flat plate, such as the
gramophone record
A phonograph record (also known as a gramophone record, especially in British English) or a vinyl record (for later varieties only) is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The g ...
. Early
BBC
The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...
technicians differentiated between ''disks'' (in-house transcription records) and ''discs'' (the colloquial term for commercial gramophone records, or what the BBC dubbed CGRs).
UK versus U.S.
By the 20th century, the "k" spelling was more popular in the United States, while the "c" variant was preferred in the UK. In the 1950s, when the American company
IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
pioneered the first
hard disk drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...
storage devices, it used the "k" spelling. Consequently, in
computer terminology today it is common for the "k" word to refer mainly to magnetic storage devices (particularly in British English, where the term ''disk'' is sometimes regarded as a contraction of ''
diskette
A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...
'', a much later word and actually a diminutive of ''disk'').
Kodak's 1982
disc film used the -c variant. The
RISC OS
RISC OS () is an operating system designed to run on ARM architecture, ARM computers. Originally designed in 1987 by Acorn Computers of England, it was made for use in its new line of ARM-based Acorn Archimedes, Archimedes personal computers an ...
, developed by the British
Acorn Computers
Acorn Computers Ltd. was a British computer company established in Cambridge, England in 1978 by Hermann Hauser, Christopher Curry (businessman), Chris Curry and Andy Hopper. The company produced a number of computers during the 1980s with asso ...
in 1987, and which was subsequently forked when Acorn stopped working on it, uses the spelling 'disc' for magnetic media.
Computer discs
Some latter-day competitors to IBM prefer the ''c''-spelling. In 1979, the Dutch company
Philips
Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarter ...
, along with
Sony
is a Japanese multinational conglomerate (company), conglomerate headquartered at Sony City in Minato, Tokyo, Japan. The Sony Group encompasses various businesses, including Sony Corporation (electronics), Sony Semiconductor Solutions (i ...
, developed and trademarked the
compact disc
The compact disc (CD) is a Digital media, digital optical disc data storage format co-developed by Philips and Sony to store and play digital audio recordings. It employs the Compact Disc Digital Audio (CD-DA) standard and was capable of hol ...
using the "c" spelling. The "c" spelling is now used consistently for optical media such as the compact disc and similar technologies.
Medical editing
The words ''disc'' and ''disk'' can appear frequently in
medical journal
A medical journal is a peer-reviewed scientific journal that communicates medical information to physicians, other health professionals. Journals that cover many medical specialties are sometimes called general medical journals.
History
The first ...
s and textbooks, especially those in
ophthalmology
Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders.
An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...
and
orthopedic
Orthopedic surgery or orthopedics ( alternative spelling orthopaedics) is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat musculoskeletal ...
s, and thus
style guide
A style guide is a set of standards for the writing, formatting, and design of documents. A book-length style guide is often called a style manual or a manual of style. A short style guide, typically ranging from several to several dozen page ...
s often foster consistency by giving rules for which contexts take which spelling.
AMA style for this topic is used by many publications. AMA says, "For ophthalmologic terms, use ''disc'' (e.g., ''optic disc''); for other anatomical terms, use ''disk'' (e.g., ''lumbar disk''). In discussions related to computers, use ''disk'' (e.g., ''floppy disk, disk drive, diskette'') (exceptions: ''compact disc, videodisc'')."
Sports
Disc sports, or disc games, are a category of activities which involve throwing and/or catching a
flying disc. Participants of disc sports consistently use the "c" spelling when describing the sports equipment used in these activities, which includes team sports such as
ultimate or individual sports such as
disc golf. This is a parallel to the spelling of "discus," the flat and round weight thrown in the track and field sport
discus throw
The discus throw (), also known as disc throw, is a track and field sport in which the participant athlete throws an oblate spheroid weight (object), weight called a discus in an attempt to mark a further distance than other competitors. It is a ...
.
References
Further reading
Apple Support Document HT2300: What's the difference between a "disc" and a "disk?"{{refend
Disc
American and British English differences
Disc