If you were looking for the C, C++, or C# programming languages then see C programming language, C++ programming language, C# programming language or Cω programming language.

If you were looking for the defunct computer magazine, see C (magazine).

If you were looking for the symbol representing Einstein's Constant, see the speed of light.

C is the third letter of the Roman alphabet.

In the Etruscan language, plosive consonants had no distinctive voicing, so they took over Greek Γ (Gamma) to write their /k/. In the beginning, the Romans used C for both /k/ and /g/, only later adding a horizontal bar at right-center to produce G. It is possible but uncertain that C represented only /g/ at an even earlier time, while K might have been used for /k/.

Some scholars claim that the Semitic ג (gîmel) pictured a camel.

Phonetic use

/k/ developed palatal and velar allophones in Latin, probably due to Etruscan influence. The Romance languages and English have a common feature inherited from Vulgar Latin where C takes on either a "hard" or "soft" value depending on the following vowel. In English and French, C takes the "hard" value [[voiceless velar plosive|]] finally and before A, O, and U, and the "soft" value /s/ before E, I, or Y. Romance languages obey similar rules, but the soft value is different in several languages, taking on /θ/ in European Castilian and /ʧ/ (like English CH) in Italian and Romanian.

Other languages use C with different values, such as /k/ regardless of position in Welsh, /θ/ in Fijian, /ʤ/ in Turkish, Tatar, Azeri, /ʦ/ in Czech, Croatian, Esperanto, Hungarian, Romanized Chinese.

There are several common digraphs with C, the most common being CH, which in some languages such as German is far more common than C alone. In English, CH most commonly takes the value /ʧ/, but can take the value /k/ or /x/, usually when transliterating Greek Χ or Hebrew. CH takes various values in other languages, such as /ç/, /k/, or /x/ in German, /ʃ/ in French, /k/ in Italian, /ʈʂʰ/ in Mandarin Chinese, and so forth. CK, with the value /k/, is often used after short vowels in Germanic languages such as English, German and Swedish. The digraph CZ is found in Polish and CS in Hungarian, both representing /ʧ/.

As a phonetic symbol, lowercase c is the International Phonetic Alphabet and X-SAMPA symbol for the voiceless palatal plosive, and capital C is the X-SAMPA symbol for the voiceless palatal fricative.

Alternate representations

Charlie represents the letter C in the NATO phonetic alphabet.

In international Morse code the letter C is DahDitDahDit: - · - ·

In Braille the letter C is represented as ⠉ (in Unicode), the dot pattern,

XX
..
..

Computing

In Unicode the capital C is codepoint U+0043 and the lowercase c is U+0063.

The ASCII code for capital C is 67 and for lowercase c is 99; or in binary 01000011 and 01100011, respectively.

The EBCDIC code for capital C is 195 and for lowercase c is 131.

The numeric character references in HTML and XML are "C" and "c" for upper and lower case respectively.

Meanings for C

• In baseball, C is the abbreviation for the position of catcher.
• In biochemistry, C is the symbol for cysteine and cytosine.
• In business, C is a "creation" initial. It is used for the company name etc. in many Japanese companies.
• In chemistry, C is the symbol for carbon.
• In the CMYK color model, C stands for the color cyan.
• In communication, c is an abbreviation for the word "see" in SMS or instant message.
• In computing, C denotes the C programming language. Several of its derivatives have names including the letter C, for example C++, Objective-C, and C#.
• In currency, c with a vertical bar through it (¢), is the symbol for cent.
• In education, C is an average grade.
• In electrical engineering,
  • C is the control grid bias power supply (originally a battery) of vacuum tube circuitry.
  • C is the variable for capacitance, and is used to label capacitors on schematics.
  • C is a standard size of dry-cell battery.
• In espionage, C is the head of MI6.
• In financial securities, C is the stock symbol for Citigroup.
• In geometry, c is the length of a hypotenuse on a right-angled triangle when using the formula a² + b² = c².
• In hardware, a C-clamp is a type of fastener, so called because its shape resembles the capital C.
• In history, c is an abbreviation for circa. When used with years, it means about (e.g., "c. 1500" means around the year 1500).
• In international relations, C sometimes represents the Commonwealth of Nations.
• In international licence plate codes, C stands for Cuba.
• In international paper sizes, C is a series of sizes with an aspect ratio of roughly 70% width to height. This series is primarily used for envelopes.
• In mathematics,
  • C is often used as a digit meaning twelve in hexadecimal and other positional numeral systems with a radix of 13 or greater.
  • Blackboard bold denotes the set of complex numbers
  • C with indices denotes the number of combinations, a binomial coefficient.
  • Blackletter denotes the cardinality of the set of real numbers (the "continuum"), or of the power set of natural numbers.
• In the Metric system,
  • c, centi, is an SI prefix meaning 1/100.
  • C is the symbol for coulomb, the SI derived unit for electric charge.
• In music, C is a note; see also Middle C
• In nutrition, C is a vitamin; see Vitamin C
• In physics,
  • c is the speed of light in vacuum.
  • c is the symbol of the charm quark.
• As the first letter of a postal code,
  • In Canada, C stands for Prince Edward Island.
• In publishing, c with an enclosing circle, ©, denotes copyright
• In rail transport, C is the UIC classification for the railroad locomotive wheel arrangement known as 0-6-0 in the Whyte notation; a locomotive with three powered axles (and thus six wheels) in which the axles are linked by gearing or side rods .
• In Roman naming convention, C is the abbreviation for the praenomen Gaius.
• In Roman numerals, C denotes one hundred (centum in Latin).
• In temperature, °C is the symbol for degrees Celsius.
• As a timezone, C is the military designation for UTC+3, also known as MSK or Moscow Time.
• In economics, C is usually used to represent consumption.
• In Chinese it is used to represent a vocal sound for foreigners not familiar with Ping Ing.

See also

• Ç, Ĉ, ¢
• С : Es (Cyrillic)