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		<summary type="html">&lt;p&gt;Imported from Wikipedia (overwrite)&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;{{short description|Unit of information}}&lt;br /&gt;
{{About|the unit of information}}&lt;br /&gt;
{{Use dmy dates|date=December 2020|cs1-dates=y}}&lt;br /&gt;
{{Fundamental info units}}&lt;br /&gt;
&lt;br /&gt;
The &amp;#039;&amp;#039;&amp;#039;bit&amp;#039;&amp;#039;&amp;#039; is the most basic [[unit of information]] in [[computing]] and digital [[communication]]. The name is a [[portmanteau]] of &amp;#039;&amp;#039;&amp;#039;binary digit&amp;#039;&amp;#039;&amp;#039;.&amp;lt;ref name=&amp;quot;Mackenzie_1980&amp;quot;/&amp;gt; The bit represents a [[truth value|logical state]] with one of two possible [[value (computer science)|values]]. These values are most commonly represented as {{nowrap|&amp;#039;&amp;#039;{{mono|1}}&amp;#039;&amp;#039; and &amp;#039;&amp;#039;{{mono|0}}&amp;#039;&amp;#039;}}, but other representations such as &amp;#039;&amp;#039;true&amp;#039;&amp;#039;/&amp;#039;&amp;#039;false&amp;#039;&amp;#039;, &amp;#039;&amp;#039;yes&amp;#039;&amp;#039;/&amp;#039;&amp;#039;no&amp;#039;&amp;#039;, &amp;#039;&amp;#039;on&amp;#039;&amp;#039;/&amp;#039;&amp;#039;off&amp;#039;&amp;#039;, and &amp;#039;&amp;#039;+&amp;#039;&amp;#039;/&amp;#039;&amp;#039;−&amp;#039;&amp;#039; are also widely used.&lt;br /&gt;
&lt;br /&gt;
The relation between these values and the physical states of the underlying [[Data storage device|storage]] or [[computing device|device]] is a matter of convention, and different assignments may be used even within the same device or [[computer program|program]]. It may be physically implemented with a two-state device.&lt;br /&gt;
&lt;br /&gt;
A contiguous group of binary digits is commonly called a &amp;#039;&amp;#039;[[bit string]]&amp;#039;&amp;#039;, a bit vector, or a single-dimensional (or multi-dimensional) &amp;#039;&amp;#039;[[bit array]]&amp;#039;&amp;#039;. A group of eight bits is called one &amp;#039;&amp;#039;[[byte]]&amp;#039;&amp;#039;, but historically, the size of the byte is not strictly defined.&amp;lt;ref name=&amp;quot;Bemer_2000&amp;quot;/&amp;gt; Frequently, half, full, double and quadruple [[Word (computer architecture)|words]] consist of a number of bytes which is a low power of two. A string of four bits is usually a &amp;#039;&amp;#039;[[nibble]]&amp;#039;&amp;#039;.&lt;br /&gt;
&lt;br /&gt;
In [[information theory]], one bit is the [[information entropy]] of a random [[Binary number|binary]] variable that is {{mono|0}} or {{mono|1}} with equal probability,&amp;lt;ref name=&amp;quot;Anderson_2006&amp;quot;/&amp;gt; or the information that is gained when the value of such a variable becomes known.&amp;lt;ref name=&amp;quot;Haykin_2006&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;IEEE_260&amp;quot;/&amp;gt; As a [[unit of information]], the bit is also known as a &amp;#039;&amp;#039;[[shannon (unit)|shannon]]&amp;#039;&amp;#039;,&amp;lt;ref name=&amp;quot;Rowlett&amp;quot;/&amp;gt; named after [[Claude E. Shannon]].  As a measure of the length of a digital string that is encoded as symbols over a binary alphabet (i.e. &amp;lt;math&amp;gt;\Sigma = \{\texttt{0}, \texttt{1}\}&amp;lt;/math&amp;gt;), the bit has been called a binit,&amp;lt;ref&amp;gt;{{cite thesis |last1=Breipohl |first1=Arthur M. |title=Adaptive Communication Systems |degree=Ph.D. |date=1963-08-18 |publisher=University of New Mexico |page=7 |url=https://digitalrepository.unm.edu/ece_etds/425/ |access-date=7 January 2025}}&amp;lt;/ref&amp;gt; but this usage is now rare.&amp;lt;ref&amp;gt;{{cite dictionary |title=binit |url=https://www.thefreedictionary.com/binit |dictionary=The Free Dictionary |access-date=7 January 2025}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
In [[data compression]], the goal is to find a shorter representation for a string, so that it requires fewer bits when stored or transmitted; the string would be compressed into the shorter representation before doing so, and then decompressed into its original form when read from storage or received. The field of [[algorithmic information theory]] is devoted to the study of the irreducible information content of a string (i.e., its shortest-possible representation length, in bits), under the assumption that the receiver has minimal &amp;#039;&amp;#039;a priori&amp;#039;&amp;#039; knowledge of the method used to compress the string. In [[error detection and correction]], the goal is to add redundant data to a string, to enable the detection or correction of errors during storage or transmission; the redundant data would be computed before doing so, and stored or transmitted, and then checked or corrected when the data is read or received.&lt;br /&gt;
&lt;br /&gt;
The symbol for the binary digit is either &amp;quot;bit&amp;quot;, per the [[IEC 80000-13]]:2008 standard, or the lowercase character &amp;quot;b&amp;quot;, per the [[IEEE 1541-2002]] standard. Use of the latter may create confusion with the capital &amp;quot;B&amp;quot;, which is the international standard symbol for the byte.&lt;br /&gt;
&lt;br /&gt;
== History ==&lt;br /&gt;
&lt;br /&gt;
[[Ralph Hartley]] suggested the use of a logarithmic measure of information in 1928.&amp;lt;ref name=&amp;quot;Abramson_1963&amp;quot;/&amp;gt; [[Claude E. Shannon]] first used the word &amp;quot;bit&amp;quot; in his seminal 1948 paper &amp;quot;[[A Mathematical Theory of Communication]]&amp;quot;.&amp;lt;ref name=&amp;quot;Shannon_1948_1&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;Shannon_1948_2&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;Shannon_1949&amp;quot;/&amp;gt; He attributed its origin to [[John W. Tukey]], who had written a Bell Labs memo on 9 January 1947 in which he contracted &amp;quot;binary digit&amp;quot; to simply &amp;quot;bit&amp;quot;.&amp;lt;ref name=&amp;quot;Shannon_1948_1&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Physical representation &amp;lt;span class=&amp;quot;anchor&amp;quot; id=&amp;quot;Representation&amp;quot;&amp;gt;&amp;lt;/span&amp;gt; ==&lt;br /&gt;
&amp;lt;!-- Warning: this heading is the target of a link in [[Flip-flop (electronics)]] --&amp;gt;&lt;br /&gt;
A bit can be stored by a digital device or other physical system that exists in either of two possible distinct [[state (computer science)|states]]. These may be the two stable states of a [[Flip-flop (electronics)|flip-flop]], two positions of an [[electrical switch]], two distinct [[voltage]] or [[electric current|current]] levels allowed by a [[electrical circuit|circuit]], two distinct levels of [[Irradiance|light intensity]], two directions of [[magnetism|magnetization]] or [[electrical polarity|polarization]], the orientation of reversible double stranded [[DNA]], etc.&lt;br /&gt;
&lt;br /&gt;
Perhaps the earliest example of a binary storage device was the [[punched card]] invented by [[Basile Bouchon]] and Jean-Baptiste Falcon (1732), developed by [[Joseph Marie Jacquard]] (1804), and later adopted by [[Semyon Korsakov]], [[Charles Babbage]], [[Herman Hollerith]], and early computer manufacturers like [[IBM]]. A variant of that idea was the perforated [[paper tape]]. In all those systems, the medium (card or tape) conceptually carried an array of hole positions; each position could be either punched through or not, thus carrying one bit of information per potential hole location. The encoding of text by bits was also used in [[Morse code]] (1844) and early digital communications machines such as [[teleprinter]]s (1870).&lt;br /&gt;
&lt;br /&gt;
The first electrical devices for discrete logic (such as [[elevator]] and [[traffic light]] control [[Electronic circuit|circuits]], [[telephone switches]], and Konrad Zuse&amp;#039;s computer) represented bits as the states of [[electrical relay]]s which could be either &amp;quot;open&amp;quot; or &amp;quot;closed&amp;quot;. These relays functioned as mechanical switches, physically toggling between states to represent binary data, forming the fundamental building blocks of early computing and control systems. When relays were replaced by [[vacuum tube]]s, starting in the 1940s, computer builders experimented with a variety of storage methods, such as pressure pulses traveling down a [[mercury delay line]], charges stored on the inside surface of a [[cathode ray tube]], or opaque spots printed on [[optical disc|glass discs]] by [[photolithographic]] techniques.&lt;br /&gt;
&lt;br /&gt;
In the 1950s and 1960s, these methods were largely supplanted by [[magnetic storage]] devices such as [[magnetic-core memory]], [[magnetic tape]]s, [[magnetic drum|drums]], and [[Disk storage|disks]], where a bit was represented by the polarity of [[magnetism|magnetization]] of a certain area of a [[ferromagnetic]] film, or by a change in polarity from one direction to the other. The same principle was later used in the [[magnetic bubble memory]] developed in the 1980s, and is still found in various [[magnetic strip]] items such as [[Rapid transit|metro]] tickets and some [[credit card]]s.&lt;br /&gt;
&lt;br /&gt;
In modern [[semiconductor memory]], such as [[dynamic random-access memory]] or a [[solid-state drive]], the two values of a bit are represented by two levels of [[electric charge]] stored in a [[capacitor]] or a [[floating-gate MOSFET]]. In certain types of [[programmable logic array]]s and [[read-only memory]], a bit may be represented by the presence or absence of a conducting path at a certain point of a circuit. In [[optical disc]]s, a bit is encoded as the presence or absence of a [[microscopic]] pit on a reflective surface. In one-dimensional [[bar code]]s and two-dimensional [[QR codes]], bits are encoded as lines or squares which may be either black or white.&lt;br /&gt;
&lt;br /&gt;
In modern digital computing, bits are transformed in Boolean [[logic gate]]s.&lt;br /&gt;
&lt;br /&gt;
=== Transmission and processing ===&lt;br /&gt;
Bits are transmitted one at a time in [[serial transmission]]. By contrast, multiple bits are transmitted simultaneously in a [[parallel transmission]]. A [[serial computer]] processes information in either a bit-serial or a byte-serial fashion.  From the standpoint of data communications, a byte-serial transmission is an 8-way parallel transmission with binary signalling.&lt;br /&gt;
&lt;br /&gt;
In programming languages such as [[C (programming language)|C]], a [[bitwise operation]] operates on binary strings as though they are vectors of bits, rather than interpreting them as [[binary number]]s.&lt;br /&gt;
&lt;br /&gt;
Data transfer rates are usually measured in decimal SI multiples.  For example, a [[channel capacity]] may be specified as 8 kbit/s = 1 kB/s.&lt;br /&gt;
&lt;br /&gt;
=== Storage ===&lt;br /&gt;
&lt;br /&gt;
File sizes are often measured in (binary) IEC multiples of bytes, for example, 1&amp;amp;nbsp;KiB&amp;amp;nbsp;= 1024 bytes&amp;amp;nbsp;= 8192 bits.  Confusion may arise in cases where (for historic reasons) file sizes are specified with binary multipliers using the ambiguous prefixes K, M, and G rather than the IEC standard prefixes Ki, Mi, and Gi.&amp;lt;ref&amp;gt;{{cite web |title=UnitsPolicy - Ubuntu Wiki |url=https://wiki.ubuntu.com/UnitsPolicy |access-date=7 January 2025}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Mass storage devices are usually measured in decimal SI multiples, for example, 1&amp;amp;nbsp;TB&amp;amp;nbsp;= &amp;lt;math&amp;gt;10^{12}&amp;lt;/math&amp;gt; bytes.&lt;br /&gt;
&lt;br /&gt;
Confusingly, the storage capacity of a directly addressable memory device, such as a [[DRAM]] chip, or an assemblage of such chips on a memory module, is specified as a binary multiple—using the ambiguous prefix G rather than the IEC recommended Gi prefix.  For example, a DRAM chip that is specified (and advertised) as having &amp;#039;&amp;#039;1&amp;amp;nbsp;GB&amp;#039;&amp;#039; of capacity has &amp;lt;math&amp;gt;2^{30}&amp;lt;/math&amp;gt; bytes of capacity.  As of 2022, the difference between the popular understanding of a memory system with &amp;#039;&amp;#039;8&amp;amp;nbsp;GB&amp;#039;&amp;#039; of capacity and the SI-correct meaning of &amp;#039;&amp;#039;8&amp;amp;nbsp;GB&amp;#039;&amp;#039; was still causing difficulty to software designers.&amp;lt;ref&amp;gt;{{cite web |title=Use MB/GB/TB suffix for VM memory input |url=https://github.com/netbox-community/netbox/issues/8437 |website=Github Netbox Community |access-date=8 January 2025 |date=2022}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Unit and symbol ==&lt;br /&gt;
The bit is not defined in the [[International System of Units]] (SI). However, the [[International Electrotechnical Commission]] issued standard [[IEC 60027]], which specifies that the symbol for binary digit should be bit, and this should be used in all multiples, such as kbit, for kilobit.&amp;lt;ref name=&amp;quot;NIST_2008&amp;quot;/&amp;gt; However, the lower-case letter &amp;#039;&amp;#039;b&amp;#039;&amp;#039; is widely used as well and was recommended by the [[IEEE 1541-2002|IEEE 1541 Standard (2002)]]. In contrast, the upper case letter B is the standard and customary symbol for byte.&lt;br /&gt;
&lt;br /&gt;
=== Multiple bits ===&lt;br /&gt;
{{redirect2|MBit|Tbit|the technical high school|MBIT|the international terminal in Los Angeles International Airport (LAX)|TBIT}}&lt;br /&gt;
{| style=&amp;quot;text-align: left; float:right; clear:right; margin-left:1em; border:1px #aaa solid; font-size:88%;&amp;quot;&lt;br /&gt;
! colspan=&amp;quot;2&amp;quot; style=&amp;quot;background-color:#ccf;padding-left:3em;padding-right:1em;text-align:center;&amp;quot;|{{resize|120%|Multiple-bit units}}&lt;br /&gt;
|-&lt;br /&gt;
| style=&amp;quot;padding:0&amp;quot; |&lt;br /&gt;
{| style=&amp;quot;border:1px #AAA solid&amp;quot;&lt;br /&gt;
!colspan=&amp;quot;4&amp;quot; style=&amp;quot;background-color:#ccf;text-align:center;&amp;quot; | [[Decimal]]&lt;br /&gt;
|-&lt;br /&gt;
!style=&amp;quot;background-color:#ddf;text-align:center;padding:0&amp;quot;| Value&lt;br /&gt;
!colspan=&amp;quot;2&amp;quot; style=&amp;quot;background-color:#ddf;text-align:center;padding:0&amp;quot;| [[SI]] ([[Metric prefix|Metric]])&lt;br /&gt;
|-&lt;br /&gt;
| 1000&lt;br /&gt;
| kbit || kilobit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Mbit || megabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Gbit || gigabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;4&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Tbit || terabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Pbit || petabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Ebit || exabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Zbit || zettabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Ybit || yottabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Rbit || ronnabit&lt;br /&gt;
|-&lt;br /&gt;
| 1000&amp;lt;sup&amp;gt;10&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Qbit || quettabit&lt;br /&gt;
|}&lt;br /&gt;
|&lt;br /&gt;
{| style=&amp;quot;border:1px #AAA solid&amp;quot;&lt;br /&gt;
!colspan=&amp;quot;6&amp;quot; style=&amp;quot;background-color:#ccf;text-align:center;&amp;quot; | [[Binary prefix|Binary]]&lt;br /&gt;
|-&lt;br /&gt;
!style=&amp;quot;background-color:#ddf;padding:0; text-align: center&amp;quot;| Value&lt;br /&gt;
!colspan=&amp;quot;2&amp;quot; style=&amp;quot;background-color:#ddf;text-align:center;padding:0&amp;quot;| [[IEC 80000-13|IEC]] &lt;br /&gt;
!colspan=&amp;quot;3&amp;quot; style=&amp;quot;background-color:#ddf;text-align:center;padding:0&amp;quot;| [[JEDEC memory standards|JEDEC]]&lt;br /&gt;
|-&lt;br /&gt;
| 1024&lt;br /&gt;
| Kibit || kibibit&lt;br /&gt;
| Kbit || Kb || kilobit&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Mibit || mebibit&lt;br /&gt;
| Mbit || Mb || megabit&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Gibit || gibibit&lt;br /&gt;
| Gbit  || Gb || gigabit&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;4&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Tibit || tebibit&lt;br /&gt;
| colspan=&amp;quot;3&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Pibit || pebibit&lt;br /&gt;
| colspan=&amp;quot;3&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Eibit || exbibit&lt;br /&gt;
| colspan=&amp;quot;3&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Zibit || zebibit&lt;br /&gt;
| colspan=&amp;quot;3&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Yibit || yobibit&lt;br /&gt;
| colspan=&amp;quot;3&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Ribit || robibit&lt;br /&gt;
| colspan=&amp;quot;3&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|-&lt;br /&gt;
| 1024&amp;lt;sup&amp;gt;10&amp;lt;/sup&amp;gt;&lt;br /&gt;
| Qibit || quebibit&lt;br /&gt;
| colspan=&amp;quot;6&amp;quot; style=&amp;quot;text-align:center;&amp;quot; | &amp;amp;mdash;&lt;br /&gt;
|}&lt;br /&gt;
|-&lt;br /&gt;
|colspan=&amp;quot;6&amp;quot; style=&amp;quot;background-color:#ddf;text-align:center;&amp;quot;| [[Orders of magnitude (data)|Orders of magnitude of data]]&lt;br /&gt;
|}&lt;br /&gt;
Multiple bits may be expressed and represented in several ways. For convenience of representing commonly reoccurring groups of bits in information technology, several [[units of information]] have traditionally been used. The most common is the unit [[byte]], coined by [[Werner Buchholz]] in June 1956, which historically was used to represent the group of bits used to encode a single [[character (computing)|character]] of text in a computer&amp;lt;ref name=&amp;quot;Bemer_2000&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;Buchholz_1956&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;Buchholz_1977&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;Buchholz_1962&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;Bemer_1959&amp;quot;/&amp;gt; and for this reason it was used as the basic [[address space|addressable]] element in many [[computer architecture]]s. By 1993, the trend in hardware design had converged on the 8-bit [[byte]].&amp;lt;ref&amp;gt;{{cite web |title=ISO/IEC 2382-1:1993(en) Information technology — Vocabulary — Part 1: Fundamental terms |url=https://www.iso.org/obp/ui/#iso:std:iso-iec:2382:-1:ed-3:v1:en |access-date=8 January 2025 |page=01.02.09}}&amp;lt;/ref&amp;gt;  However, because of the ambiguity of relying on the underlying hardware design, the unit [[Octet (computing)|octet]] was defined to explicitly denote a sequence of eight&amp;amp;nbsp;bits.&lt;br /&gt;
&lt;br /&gt;
Computers usually manipulate bits in groups of a fixed size, conventionally named &amp;quot;[[Word (computer architecture)|words]]&amp;quot;. Like the byte, the number of bits in a word also varies with the hardware design, and is typically between 8 and 80&amp;amp;nbsp;bits, or even more in some specialized computers. In the early 21st century, retail personal or server computers have a word size of 32 or 64&amp;amp;nbsp;bits.&lt;br /&gt;
&lt;br /&gt;
The [[International System of Units]] defines a series of decimal prefixes for multiples of standardized units, which are commonly also used with the bit and the byte. The prefixes [[kilo-|kilo]] (10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;) through [[quetta-|quetta]] (10&amp;lt;sup&amp;gt;30&amp;lt;/sup&amp;gt;) increment by multiples of one thousand, and the corresponding units are the [[kilobit]] (kbit) through the [[quettabit]] (Qbit).&lt;br /&gt;
&lt;br /&gt;
== See also ==&lt;br /&gt;
* {{Annotated link|Baud}}&lt;br /&gt;
* {{Annotated link|Binary numeral system}}&lt;br /&gt;
* {{Annotated link|Bit rate}}&lt;br /&gt;
* {{Annotated link|Bitstream}}&lt;br /&gt;
* {{Annotated link|Entropy (information theory)}}&lt;br /&gt;
* {{Annotated link|Fuzzy bit}}&lt;br /&gt;
* {{Annotated link|Integer (computer science)}}&lt;br /&gt;
* {{Annotated link|Primitive data type}}&lt;br /&gt;
* {{Annotated link|Qubit}} (quantum bit)&lt;br /&gt;
* {{Annotated link|Shannon (unit)}}&lt;br /&gt;
* Trit – {{Annotated link|Ternary numeral system}} (ternary digit)&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
&amp;lt;references&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Mackenzie_1980&amp;quot;&amp;gt;{{cite book |url=https://textfiles.meulie.net/bitsaved/Books/Mackenzie_CodedCharSets.pdf |title=Coded Character Sets, History and Development |series=The Systems Programming Series |author-last=Mackenzie |author-first=Charles E. |date=1980 |edition=1 |publisher=[[Addison-Wesley Publishing Company, Inc.]] |isbn=978-0-201-14460-4 |lccn=77-90165 |page=x |access-date=2019-08-25 |archive-url=https://web.archive.org/web/20160526172151/https://textfiles.meulie.net/bitsaved/Books/Mackenzie_CodedCharSets.pdf |archive-date=May 26, 2016 |url-status=live |df=mdy-all }}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Anderson_2006&amp;quot;&amp;gt;{{citation |author-first1=John B. |author-last1=Anderson |author-first2=Rolf |author-last2=Johnnesson |date=2006 |title=Understanding Information Transmission}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Haykin_2006&amp;quot;&amp;gt;{{citation |author-first=Simon |author-last=Haykin |date=2006 |title=Digital Communications}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;IEEE_260&amp;quot;&amp;gt;[[IEEE Std 260.1-2004]]&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Rowlett&amp;quot;&amp;gt;{{cite web |url=https://www.unc.edu/~rowlett/units/dictB.html#bit |title=Units: B |url-status=live |archive-url=https://web.archive.org/web/20160504055432/http://www.unc.edu/~rowlett/units/dictB.html#bit |archive-date=2016-05-04}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Abramson_1963&amp;quot;&amp;gt;{{cite book |author-first=Norman |author-last=Abramson |date=1963 |title=Information theory and coding |publisher=[[McGraw-Hill]]}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;NIST_2008&amp;quot;&amp;gt;National Institute of Standards and Technology (2008), &amp;#039;&amp;#039;Guide for the Use of the International System of Units&amp;#039;&amp;#039;. [http://physics.nist.gov/cuu/pdf/sp811.pdf Online version.] {{webarchive|url=https://web.archive.org/web/20160603203340/http://physics.nist.gov/cuu/pdf/sp811.pdf |date=3 June 2016}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;!-- UNUSED REF &amp;lt;ref name=&amp;quot;Bush_1936&amp;quot;&amp;gt;{{cite journal |author-last=Bush |author-first=Vannevar |author-link=Vannevar Bush |title=Instrumental analysis |journal=[[Bulletin of the American Mathematical Society]] |date=1936 |volume=42 |issue=10 |pages=649–669 |url=http://projecteuclid.org/euclid.bams/1183499313 |doi=10.1090/S0002-9904-1936-06390-1 |url-status=live |archive-url=https://web.archive.org/web/20141006153002/http://projecteuclid.org/euclid.bams/1183499313 |archive-date=2014-10-06|doi-access=free }}&amp;lt;/ref&amp;gt; --&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Shannon_1948_1&amp;quot;&amp;gt;{{cite journal |author-last=Shannon |author-first=Claude Elwood |author-link=Claude Elwood Shannon |title=A Mathematical Theory of Communication |journal=[[Bell System Technical Journal]] |volume=27 |issue=3 |pages=379–423 |date=July 1948 |doi=10.1002/j.1538-7305.1948.tb01338.x |bibcode=1948BSTJ...27..379S |hdl=11858/00-001M-0000-002C-4314-2 |url=http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf |via=Bell Labs Computing and Mathematical Sciences Research |archive-url=https://web.archive.org/web/19980715013250/http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf |url-status=dead |archive-date=1998-07-15 |quote=The choice of a logarithmic base corresponds to the choice of a unit for measuring information. If the base 2 is used the resulting units may be called binary digits, or more briefly &amp;#039;&amp;#039;bits&amp;#039;&amp;#039;, a word suggested by [[J. W. Tukey]].|hdl-access=free }}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Shannon_1948_2&amp;quot;&amp;gt;{{cite journal |author-last=Shannon |author-first=Claude Elwood |author-link=Claude Elwood Shannon |title=A Mathematical Theory of Communication |journal=[[Bell System Technical Journal]] |volume=27 |issue=4 |pages=623–666 |date=October 1948 |doi=10.1002/j.1538-7305.1948.tb00917.x |bibcode=1948BSTJ...27..623S |hdl=11858/00-001M-0000-002C-4314-2|hdl-access=free }}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Shannon_1949&amp;quot;&amp;gt;{{cite book |author-last1=Shannon |author-first1=Claude Elwood |author-link1=Claude Elwood Shannon |author-first2=Warren |author-last2=Weaver |author-link2=Warren Weaver |title=A Mathematical Theory of Communication |publisher=[[University of Illinois Press]] |date=1949 |isbn=0-252-72548-4 |url=http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf |via=Bell Labs Computing and Mathematical Sciences Research |archive-url=https://web.archive.org/web/19980715013250/http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf |url-status=dead |archive-date=1998-07-15}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Bemer_2000&amp;quot;&amp;gt;{{cite web |title=Why is a byte 8 bits? Or is it? |author-first=Robert William |author-last=Bemer |author-link=Robert William Bemer |date=2000-08-08 |work=Computer History Vignettes |url=http://www.bobbemer.com/BYTE.HTM |access-date=2017-04-03 |url-status=dead |archive-url=https://web.archive.org/web/20170403130829/http://www.bobbemer.com/BYTE.HTM |archive-date=2017-04-03 |quote=[...] With [[IBM]]&amp;#039;s [[STRETCH]] computer as background, handling 64-character words divisible into groups of 8 (I designed the character set for it, under the guidance of Dr. [[Werner Buchholz]], the man who DID coin the term &amp;quot;[[byte]]&amp;quot; for an 8-bit grouping). [...] The [[IBM 360]] used 8-bit characters, although not ASCII directly. Thus Buchholz&amp;#039;s &amp;quot;byte&amp;quot; caught on everywhere. I myself did not like the name for many reasons. [...]}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Buchholz_1956&amp;quot;&amp;gt;{{cite book |title=The Link System |chapter=7. The Shift Matrix |author-first=Werner |author-last=Buchholz |author-link=Werner Buchholz |date=1956-06-11 |id=[[IBM Stretch|Stretch]] Memo No. 39G |publisher=[[IBM]] |pages=5–6 |chapter-url=http://archive.computerhistory.org/resources/text/IBM/Stretch/pdfs/06-07/102632284.pdf |access-date=2016-04-04 |url-status=live |archive-url=https://web.archive.org/web/20170404152534/http://archive.computerhistory.org/resources/text/IBM/Stretch/pdfs/06-07/102632284.pdf |archive-date=2017-04-04 |quote=[...] Most important, from the point of view of editing, will be the ability to handle any characters or digits, from 1 to 6 bits long [...] the Shift Matrix to be used to convert a 60-bit [[word (computer architecture)|word]], coming from Memory in parallel, into [[character (computing)|characters]], or &amp;quot;[[byte]]s&amp;quot; as we have called them, to be sent to the [[serial adder|Adder]] serially. The 60 bits are dumped into [[magnetic core]]s on six different levels. Thus, if a 1 comes out of position 9, it appears in all six cores underneath. [...] The Adder may accept all or only some of the bits. [...] Assume that it is desired to operate on 4 bit [[decimal digit]]s, starting at the right. The 0-diagonal is pulsed first, sending out the six bits 0 to 5, of which the Adder accepts only the first four (0-3). Bits 4 and 5 are ignored. Next, the 4 diagonal is pulsed. This sends out bits 4 to 9, of which the last two are again ignored, and so on. [...] It is just as easy to use all six bits in [[alphanumeric]] work, or to handle bytes of only one bit for logical analysis, or to offset the bytes by any number of bits. [...]}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Buchholz_1977&amp;quot;&amp;gt;{{cite journal |author-last=Buchholz |author-first=Werner |author-link=Werner Buchholz |title=The Word &amp;quot;Byte&amp;quot; Comes of Age... |journal=[[Byte Magazine]] |date=February 1977 |volume=2 |issue=2 |page=144 |url=https://archive.org/stream/byte-magazine-1977-02/1977_02_BYTE_02-02_Usable_Systems#page/n145/mode/2up |quote=[...] The first reference found in the files was contained in an internal memo written in June 1956 during the early days of developing [[IBM Stretch|Stretch]]. A [[byte]] was described as consisting of any number of parallel bits from one to six. Thus a byte was assumed to have a length appropriate for the occasion. Its first use was in the context of the input-output equipment of the 1950s, which handled six bits at a time. The possibility of going to 8 bit bytes was considered in August 1956 and incorporated in the design of Stretch shortly thereafter. The first published reference to the term occurred in 1959 in a paper &amp;quot;Processing Data in Bits and Pieces&amp;quot; by [[Gerrit Anne Blaauw|G&amp;amp;nbsp;A&amp;amp;nbsp;Blaauw]], [[Frederick Phillips Brooks, Jr.|F&amp;amp;nbsp;P&amp;amp;nbsp;Brooks&amp;amp;nbsp;Jr]] and [[Werner Buchholz|W&amp;amp;nbsp;Buchholz]] in the &amp;#039;&amp;#039;[[IRE Transactions on Electronic Computers]]&amp;#039;&amp;#039;, June 1959, page 121. The notions of that paper were elaborated in Chapter 4 of &amp;#039;&amp;#039;[[#Buchholz-1962|Planning a Computer System (Project Stretch)]]&amp;#039;&amp;#039;, edited by W&amp;amp;nbsp;Buchholz, [[McGraw-Hill Book Company]] (1962). The rationale for coining the term was explained there on page 40 as follows:&amp;lt;br /&amp;gt;Byte &amp;#039;&amp;#039;denotes a group of bits used to encode a character, or the number of bits transmitted in parallel to and from input-output units. A term other than &amp;#039;&amp;#039;character&amp;#039;&amp;#039; is used here because a given character may be represented in different applications by more than one code, and different codes may use different numbers of bits (ie, different byte sizes). In input-output transmission the grouping of bits may be completely arbitrary and have no relation to actual characters. (The term is coined from &amp;#039;&amp;#039;[[bite]]&amp;#039;&amp;#039;, but respelled to avoid accidental mutation to &amp;#039;&amp;#039;bit&amp;#039;&amp;#039;.)&amp;#039;&amp;#039;&amp;lt;br /&amp;gt;[[System/360]] took over many of the Stretch concepts, including the basic byte and word sizes, which are powers of 2. For economy, however, the byte size was fixed at the 8 bit maximum, and addressing at the bit level was replaced by byte addressing. [...]}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Buchholz_1962&amp;quot;&amp;gt;{{anchor|Buchholz-1962}}{{citation |title=Planning a Computer System – Project Stretch |author-first1=Gerrit Anne |author-last1=Blaauw |author-link1=Gerrit Anne Blaauw |author-first2=Frederick Phillips |author-last2=Brooks, Jr. |author-link2=Frederick Phillips Brooks, Jr. |author-first3=Werner |author-last3=Buchholz |author-link3=Werner Buchholz |editor-first=Werner |editor-last=Buchholz |editor-link=Werner Buchholz |publisher=[[McGraw-Hill Book Company, Inc.]] / The Maple Press Company, York, PA. |lccn=61-10466 |date=1962 |chapter=Chapter 4: Natural Data Units |pages=39–40 |chapter-url=http://archive.computerhistory.org/resources/text/IBM/Stretch/pdfs/Buchholz_102636426.pdf |access-date=2017-04-03 |url-status=dead |archive-url=https://web.archive.org/web/20170403014651/http://archive.computerhistory.org/resources/text/IBM/Stretch/pdfs/Buchholz_102636426.pdf |archive-date=2017-04-03}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;ref name=&amp;quot;Bemer_1959&amp;quot;&amp;gt;{{cite journal |author-first=Robert William |author-last=Bemer |author-link=Robert William Bemer |title=A proposal for a generalized card code of 256 characters |journal=[[Communications of the ACM]] |volume=2 |number=9 |pages=19–23 |date=1959 |doi=10.1145/368424.368435|s2cid=36115735 |doi-access=free }}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;/references&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== External links ==&lt;br /&gt;
{{wiktionary}}&lt;br /&gt;
* [https://web.archive.org/web/20090216151053/http://www.bit-calculator.com/ Bit Calculator] – a tool providing conversions between bit, byte, kilobit, kilobyte, megabit, megabyte, gigabit, gigabyte&lt;br /&gt;
* [http://nxu.biz/tools/BitXByteConverter/ BitXByteConverter] {{Webarchive|url=https://web.archive.org/web/20160406223558/http://nxu.biz/tools/BitXByteConverter/ |date=2016-04-06 }} – a tool for computing file sizes, storage capacity, and digital information in various units&lt;br /&gt;
&lt;br /&gt;
{{Information units}}&lt;br /&gt;
{{Data types}}&lt;br /&gt;
{{Authority control}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Binary arithmetic]]&lt;br /&gt;
[[Category:Primitive types]]&lt;br /&gt;
[[Category:Data types]]&lt;br /&gt;
[[Category:Units of information]]&lt;/div&gt;</summary>
		<author><name>RS-485</name></author>
	</entry>
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