CH, Ch, cH, or ch may refer to:

Arts and entertainment

* Television channel (sometimes abbreviated as "ch." for television and cable stations) * '' Chaos;Head'', a video game * '' Clone Hero'', a clone game version of popular rhythm game series '' Guitar Hero''. * CollegeHumor, a comedy website * E!, a defunct Canadian television system that went by the name CH from 2001 to 2007

Businesses

* Bemidji Airlines (IATA code CH) * Carolina Herrera, a fashion designer based in New York *

Columbia Helicopters Columbia Helicopters, Incorporated (CHI) is an aircraft manufacturing and operator company based in Aurora, Oregon, United States. It is known for operating tandem rotor helicopters; in present times, exclusively the CH-46 Sea Knight, Boeing Vert ...

, an aircraft manufacturing and operator company based in Aurora, Oregon, United States

In language

* Ch (digraph), considered a single letter in several Latin-alphabet languages * Chamorro language: ISO 639 alpha-2 language code (ch)

Science and technology

Chemistry

* The methylidyne radical (a carbyne); CH^• (or •CH), CH^3• (or ⫶CH) * The

methylidyne group In organic chemistry, a methylidyne group or just methylidyne is a neutral part of a molecule (a substituent or functional group) with formula , consisting of a carbon atom bonded to a hydrogen atom by one single bond and to the rest of the molecu ...

≡CH * The methine group (methanylylidene, methylylidene) =CH−

Mathematics and computing

* Chomsky hierarchy, in computer science, a containment hierarchy of classes of formal grammars * Continuum hypothesis, in set theory * Hyperbolic cosine, in mathematics, a hyperbolic function, ch(x) = cosh(x) *

Curry–Howard correspondence In programming language theory and proof theory, the Curry–Howard correspondence (also known as the Curry–Howard isomorphism or equivalence, or the proofs-as-programs and propositions- or formulae-as-types interpretation) is the direct relati ...

, the relationship between computer programs and mathematical proofs * CH register, the high byte of an X86 16-bit CX register * Ch (computer programming), a cross-platform C/C++ interpreter *

Contraction hierarchies In computer science, the method of contraction hierarchies is a speed-up technique for finding the shortest-path in a graph. The most intuitive applications are car-navigation systems: a user wants to drive from A to B using the quickest possibl ...

, in computer science, a speed-up technique for finding shortest paths in a graph

Medicine

* Cluster headache * Cholesterol * Congenital hypothyroidism, a condition of thyroid hormone deficiency present at birth * Cerebellar hypoplasia, characterized by reduced cerebellar volume :*

Cerebellar hypoplasia (non-human) Cerebellar hypoplasia (CH) is a neurological condition in which the cerebellum is smaller than usual or not completely developed. It has been reported in many animal species. Function and development of the cerebellum The cerebellum is the b ...

* French catheter scale, a scale for medical catheters, also abbreviated as ''Fr''

Military technology

Cargo helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

(U.S. military helicopter alpha-numeric prefix) *

Chain Home Chain Home, or CH for short, was the codename for the ring of coastal Early Warning radar stations built by the Royal Air Force (RAF) before and during the Second World War to detect and track aircraft. Initially known as RDF, and given the off ...

, a World War II radar array * Heavy cruiser (U.S. Navy ship code CH, standing for "Cruiser, Heavy")

In other sciences

* Clay of high plasticity (USCS soil type CH) * Cassini-Huygens

Places

* Confoederatio Helvetica, the formal name for Switzerland, Latin in origin ** ISO country code for Switzerland **

.ch .ch is the country code top-level domain (ccTLD) for Switzerland in the Domain Name System of the Internet. Made available in 1987, only two years after .com, it is administered by SWITCH Information Technology Services. The domain ''ch'', as ...

, the Internet country code top-level domain for Switzerland * CH postcode area; the Chester postcode area in the UK * Chihuahua (state), the State of Chihuahua, Mexico * Conservation Halton, in Ontario, Canada *

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

(FIPS and NATO country code CH)

Other uses

* Chain (length), a unit of linear measure in the Imperial system * Championship (dog), a dog qualifying for a championship at a conformation show, prefixed "Ch." * Christ's Hospital, Horsham, West Sussex *

Companion of Honour The Order of the Companions of Honour is an order of the Commonwealth realms. It was founded on 4 June 1917 by King George V as a reward for outstanding achievements. Founded on the same date as the Order of the British Empire, it is sometimes ...

, a British and Commonwealth honour *

Chaudhary Chaudhary (or Choudhary ; also: Chaudhuri, Choudhuary, Chowdhury) is a hereditary title mainly in South Asia, mainly used by Jats, Gurjar and Bhumihars. Chowdhury (Hindi: चौधरी/चौधुरी/चौधारी; Urdu: چودھر� ...

, an honorific used in the Indian and Pakistani Punjab regions * Metres above the Sea (Switzerland), an elevation reference system * The logo for the Montreal Canadiens ice hockey team {{disambiguation