''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 A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. (For example, in the human body, the brain which is part of the central nervous system re ...

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 ac ...

(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 platters coated with magn ...

s) while ''disc'' is used for optical storage (e.g.,

compact disc The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in O ...

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 varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...

, while the spelling ''disc'' is more popular in

British English British English (BrE, en-GB, or BE) is, according to Oxford Dictionaries, "English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer specifically to the English language in England, or, more broadl ...

Disk

The earlier word is ''disk'', which came into the

English language English is a West Germanic language of the Indo-European language family, with its earliest forms spoken by the inhabitants of early medieval England. It is named after the Angles, one of the ancient Germanic peoples that migrated to the ...

in the middle of the 17th century. In the 19th century, ''disk'' became the conventional spelling for

audio recording Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording t ...

s made on a flat plate, such as the

gramophone record A phonograph record (also known as a gramophone record, especially in British English), or simply a record, is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts ne ...

. Early BBC 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 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 platters coated with mag ...

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, or a diskette) is an obsolescent 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 wi ...

'', a much later word and actually a diminutive of ''disk'').

Computer discs

Some latter-day competitors to IBM prefer the ''c''-spelling. In 1979, the Dutch company

Philips Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is ...

, along with

Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...

, developed and trademarked the

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 fi ...

s and textbooks, especially those in

ophthalmology Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a me ...

and

orthopedic Orthopedic surgery or orthopedics ( alternatively spelt 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 or manual of style is a set of standards for the writing, formatting, and design of documents. It is often called a style sheet, although that term also has multiple other meanings. The standards can be applied either for gene ...

s often foster consistency by giving rules for which contexts take which spelling.

AMA style ''AMA Manual of Style: A Guide for Authors and Editors'' is the style guide of the American Medical Association. It is written by the editors of ''JAMA'' (''Journal of the American Medical Association'') and the JAMA Network journals and is most ...

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 A frisbee (pronounced ), also called a flying disc or simply a disc, is a gliding toy or sporting item that is generally made of injection-molded plastic and roughly in diameter with a pronounced lip. It is used recreationally and competitiv ...

. 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 Ultimate or Ultimates may refer to: Arts, entertainment, and media Music Albums * ''Ultimate'' (Jolin Tsai album) * ''Ultimate'' (Pet Shop Boys album) *'' Ultimate!'', an album by The Yardbirds *'' The Ultimate (Bryan Adams Album)'', a compilat ...

or individual sports such as

disc golf Disc golf, also known as frisbee golf, is a flying disc sport in which players throw a disc at a target; it is played using rules similar to golf. Most disc golf discs are made out of polypropylene plastic, otherwise known as polypropene, which ...

Disk

UK versus U.S.

Computer discs

Medical editing

Sports

References

Further reading