C is the third letter in the English alphabet and a letter of the alphabets of many other writing systems which inherited it from the Latin alphabet. It is also the third letter of the ISO basic Latin alphabet. It is named cee (pronounced ) in English.

The grapheme C (minuscule: ), formed from C with the addition of an acute accent, is used in various languages. It usually denotes , the voiceless alveolo-palatal affricate, including in phonetic transcription. Its Unicode codepoints are U+0106 for C and U+0107 for c.

C (minuscule: c) is a letter of the Latin alphabet, formed from C with the addition of a dot. It is used in Maltese to represent a voiceless postalveolar affricate, equivalent to English ch . It is occasionally used in Old English for the same reason, to distinguish it from c pronounced as , which otherwise is spelled the same. Its voiced equivalent is G.

The grapheme Cc (Latin C with hácek) is used in various contexts, usually denoting the voiceless postalveolar affricate consonant  like the English ch in the word chocolate. It is represented in Unicode as U+010C (uppercase C) and U+010D (lowercase c).

C or c (C circumflex) is a consonant in Esperanto orthography, representing the sound .

(c-cedilla) is a Latin script letter, used in the Albanian, Azerbaijani, Tatar, Turkish, Turkmen, Kurdish and Zazaki alphabets. Romance languages that use this letter include Catalan, French, Friulian, Ligurian, Occitan, and Portuguese as a variant of the letter C. It is also occasionally used in Crimean Tatar and Manx. It is often retained in the spelling of loanwords from any of these languages in English, Dutch, Spanish, Basque and other Latin script spelled languages.

C (, as in the letter c) is a general-purpose, imperative computer programming language, supporting structured programming, lexical variable scope and recursion, while a static type system prevents many unintended operations. By design, C provides constructs that map efficiently to typical machine instructions, and therefore it has found lasting use in applications that had formerly been coded in assembly language, including operating systems, as well as various application software for computers ranging from supercomputers to embedded systems.

C# (pronounced as see sharp) is a multi-paradigm programming language encompassing strong typing, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. It was developed by Microsoft within its .NET initiative and later approved as a standard by Ecma (ECMA-334) and ISO (ISO/IEC 23270:2006). C# is one of the programming languages designed for the Common Language Infrastructure.

C* is an object-oriented, data-parallel superset of ANSI C with synchronous semantics.

C+ or C Plus may refer to:

• C++, a programming language
• Orthodox C++, a "minimal subset of C++" designed to avoid some of of the perceived disadvantages of "Modern C++" code that uses the Standard Template Library
• ABCL/c+, a programming language
• C+ (grade), an academic grade
• Faster-than-light travel, above the speed of light, c
• Sunkist (soft drink), which is known as C Plus in some places
• Poorly-written C++ code that is barely object-oriented.

C++ (pronounced as cee plus plus, ) is a general-purpose programming language. It has imperative, object-oriented and generic programming features, while also providing facilities for low-level memory manipulation.

C-- (pronounced "see minus minus") is a C-like programming language. Its creators, functional programming researchers Simon Peyton Jones and Norman Ramsey, designed it to be generated mainly by compilers for very high-level languages rather than written by human programmers. Unlike many other intermediate languages, its representation is plain ASCII text, not bytecode or another binary format.

C. or c. may refer to:

• Circa: in genealogy and historical writing, c. means circa, and is used when the dates of events are approximately known
• Chapter in legal citation, c. means chapter, and is used to refer to the specific chapter number which a statute has been assigned in a volume
• Caius or Gaius in Roman name abbreviations
• C. was a pen-name used by Samuel Taylor Coleridge

In set theory, the cardinality of the continuum is the cardinality or “size” of the set of real numbers , sometimes called the continuum. It is an infinite cardinal number and is denoted by or (a lowercase fraktur script "c").

Commodore International (or Commodore International Limited) was a North American home computer and electronics manufacturer. Commodore International (CI) along with its subsidiary Commodore Business Machines (CBM) participated in the development of the home–personal computer industry in the 1970s and 1980s. The company developed and marketed one of the world's best-selling desktop computers, the Commodore 64 (1982) and released its Amiga computer line in 1985.

A complex number is a number that can be expressed in the form a + bi, where a and b are real numbers and i is the imaginary unit, that satisfies the equation i² = -1. In this expression, a is the real part and b is the imaginary part of the complex number.

Control-C is a common computer command. It is generated by pressing the key while holding down the key on most computer keyboards.

The copyright symbol, or copyright sign, © (a circled capital letter "C"), is the symbol used in copyright notices for works other than sound recordings (which are indicated with the ). The use of the symbol is described in United States copyright law, and, internationally, by the Universal Copyright Convention. The symbol is widely recognized, but under the Berne Convention is no longer required to obtain a new copyright in most nations. For instance, the United States eliminated the copyright symbol requirement as of March 1, 1989, but its presence or absence is legally significant on works published previously.

Cunt is a vulgar term for female genitalia, and is also used as a term of disparagement. Reflecting different national usages, cunt is described as "an unpleasant or stupid person" in the Compact Oxford English Dictionary, whereas Merriam-Webster indicates that it is a "usually disparaging and obscene" term for a woman or an "offensive way to refer to a woman" in the United States. The Macquarie Dictionary of Australian English gives "a contemptible person". When used with a positive qualifier (good, funny, clever, etc.) in Britain, New Zealand, and Australia, it can convey a positive sense of the object or person referred to.

In computing, drive letter assignment is the process of assigning alphabetical identifiers to volumes. Unlike the concept of UNIX mount points, where volumes are named and located arbitrarily in a single hierarchical namespace, drive letter assignment allows multiple highest-level namespaces. Drive letter assignment is thus a process of using letters to name the roots of the "forest" representing the file system; each volume holds an independent "tree" (or, for non-hierarchical file systems, an independent list of files).

Grading in education is the process of applying standardized measurements of varying levels of achievement in a course. Another way the grade point average (GPA) can be determined is through extra curricular activities. Grades can be assigned as letters (generally A through F), as a range (for example 1 to 6), as a percentage of a total number of questions answered correctly, or as a number out of a possible total (for example out of 20 or 100).

In mathematics, the Riemann sphere, named after the 19th century mathematician Bernhard Riemann, is a model of the extended complex plane, the complex plane plus a point at infinity. This extended plane represents the extended complex numbers, that is, the complex numbers plus a value 8 for infinity. With the Riemann model, the point "8" is near to very large numbers, just as the point "0" is near to very small numbers.