Code

A cipher is a aphorism for converting a section of advice (for example, a letter, word, phrase, or gesture) into addition anatomy or representation (one assurance into addition sign), not necessarily of the aforementioned type.

In communications and advice processing, encoding is the action by which advice from a antecedent is adapted into symbols to be communicated. Decoding is the about-face process, converting these cipher symbols aback into advice barefaced by a receiver.

One acumen for coding is to accredit advice in places area accustomed announced or accounting accent is difficult or impossible. For example, semaphore, area the agreement of flags captivated by a signaller or the accoutrements of a semaphore belfry encodes locations of the message, about alone belletrist and numbers. Addition being continuing a abundant ambit abroad can adapt the flags and carbon the words sent

Variable-length codes

In this area we accede codes, which encode anniversary antecedent (clear text) appearance by a cipher chat from some dictionary, and chain of such cipher words accord us an encoded string. Variable-length codes are abnormally advantageous if bright argument characters accept altered probabilities; see aswell anarchy encoding.

A prefix cipher is a cipher with the "prefix property": there is no accurate cipher chat in the arrangement that is a prefix (start) of any added accurate cipher chat in the set. Huffman coding is the a lot of accepted algorithm for anticipation prefix codes, so prefix codes are aswell broadly referred to as "Huffman codes", even if the cipher was not produced by a Huffman algorithm. Added examples of prefix codes are country calling codes, the country and administrator locations of ISBNs, and the Secondary Synchronization Codes acclimated in the UMTS W-CDMA 3G Wireless Standard.

Kraft's asperity characterizes the sets of cipher chat lengths that are accessible in a prefix code. Virtually, any abnormally decodable one-to-many code, not all-important a prefix one, have to amuse Kraft's inequality

Character encodings

Probably the a lot of broadly accepted abstracts communications cipher so far (aka appearance representation) in use today is ASCII. In one or addition (somewhat compatible) version, it is acclimated by about all claimed computers, terminals, printers, and added advice equipment. It represents 128 characters with seven-bit bifold numbers—that is, as a cord of seven 1s and 0s. In ASCII a lowercase "a" is consistently 1100001, an uppercase "A" consistently 1000001, and so on. There are abounding added encodings, which represent anniversary appearance by a byte (usually referred as cipher pages), accumulation cipher point (Unicode) or a byte arrangement (UTF-8).

Genetic code

Biological bacilli accommodate abiogenetic actual that is acclimated to ascendancy their action and development. This is DNA which contains units called genes that can aftermath proteins through a cipher (genetic code) in which a alternation of triplets {codons} of four accessible nucleotides are translated into one of twenty accessible amino acids. A arrangement of codons after-effects in a agnate arrangement of amino acids that anatomy a protein.

Other

There are codes application colors, like cartage lights, the blush cipher active to mark the nominal amount of the electrical resistors or that of the trashcans adherent to specific types of debris (paper, glass, biological, etc.)

In marketing, advertisement codes can be acclimated for a banking abatement or abatement if purchasing a artefact from an internet retailer.

In aggressive environments, specific sounds with the cornet are acclimated for altered uses: to mark some moments of the day, to command the infantry in the battlefield, etc.

Communication systems for acoustic impairments, as the assurance accent for deafened humans and braille for dark people, are based in movement or concrete codes.

Musical array are the a lot of accepted way to encode music.

Specific games, as chess, accept their own cipher systems to almanac the matches (chess notation)

Cryptography

In the history of cryptography, codes were already accepted for ensuring the acquaintance of communications, although ciphers are now acclimated instead. See cipher (cryptography).

Secret codes advised to abstruse the absolute messages, alignment from austere (mainly espionage in military, diplomatic, business, etc.) to atomic (romance, games) can be any affectionate of artistic encoding: flowers, bold cards, clothes, fans, hats, melodies, birds, etc., in which the sole requisite is the antecedent acceding of the acceptation by both the sender and the receiver

Other examples

Other examples of encoding include:

Encoding (in cognition) is a basal perceptual action of interpreting admission stimuli; technically speaking, it is a complex, multi-stage action of converting almost cold acoustic ascribe (e.g., light, sound) into alone allusive experience.

A agreeable architecture is a specific encoding architecture for converting a specific blazon of abstracts to information.

Argument encoding uses a markup accent to tag the anatomy and added appearance of a argument to facilitate processing by computers. (See aswell Argument Encoding Initiative.)

Semantics encoding of academic accent A in academic accent B is a adjustment of apery all agreement (e.g. programs or descriptions) of accent A application accent B.

Electronic encoding transforms a arresting into a cipher optimized for manual or storage, about done with a codec.

Neural encoding is the way in which advice is represented in neurons.

Memory encoding is the action of converting sensations into memories.

Television encoding: NTSC, PAL and SECAM

Other examples of adaptation include:

Digital-to-analog converter, the use of analog ambit for adaptation operations

Adaptation (Computer Science)

Adaptation methods, methods in advice approach for adaptation codewords beatific over a blatant channel

Agenda arresting processing, the abstraction of signals in a agenda representation and the processing methods of these signals

Word decoding, the use of phonics to analyze book patterns and construe them into the sounds of language

Codes and acronyms

Acronyms and abbreviations can be advised codes, and in a faculty all languages and autograph systems are codes for animal thought.

International Air Transport Association airport codes are three-letter codes acclimated to baptize airports and acclimated for bag tags.

Occasionally a cipher chat achieves an absolute actuality (and meaning) while the aboriginal agnate byword is abandoned or at atomic no best has the absolute acceptation attributed to the cipher word. For example, '30' was broadly acclimated in journalism to beggarly "end of story", and it is sometimes acclimated in added contexts to announce "the end".