# Bit

A bit (a contraction of binary digit) is the basic capacity of information in computing and telecommunications; a bit can have the value of either 1 or 0 (one or zero) only. These attributes may be implemented, in a variety of systems, by means of a two state device.

In computing, a bit can be defined as a variable or computed quantity that can have only two possible values. These two values are often interpreted as binary digits and are usually denoted by the numerical digits 0 and 1. The two values can also be interpreted as logical values (true/false, yes/no), algebraic signs (+/), activation states (on/off), or any other two-valued attribute. The correspondence between these values and the physical states of the underlying storage or device is a matter of convention, and different assignments may be used even within the same device or program. The length of a binary number may be referred to as its "bit-length".

In information theory, one bit is typically defined as the uncertainty of a binary random variable that is 0 or 1 with equal probability, or the information that is gained when the value of such a variable becomes known.

In quantum computing, a quantum bit or qubit is a quantum system that can exist in superposition of two bit values, "true" and "false".

The symbol for bit, as a unit of information, is either simply "bit" (recommended by the ISO/IEC standard 80000-13 (2008)) or lowercase "b" (recommended by the IEEE 1541 Standard (2002)).

### Other articles related to "bit, bits":

Bit - Other Information Units
... also called a nat or nit and defined as log2 e (≈ 1.443) bits, where e is the base of the natural logarithms and the dit, ban, or hartley, defined as log2 10 (≈ 3.322) bits ... Conversely, one bit of information corresponds to about ln 2 (≈ 0.693) nats, or log10 2 (≈ 0.301) hartleys ... a binit as an arbitrary information unit equivalent to some fixed but unspecified number of bits ...
Modified AMI Code - Zero Code Suppression
... a minimum density of marks was zero code suppression a form of bit stuffing, which set the least significant bit of each 8-bit byte transmitted to a 1 ... (This bit was already unavailable due to robbed-bit signaling.) This avoided the need to modify the AMI code in any way, but limited available data rates to 56,000 bits per second per DS0 voice channel ... for bandwidth, and compatibility with the G.703 and ISDN PRI standards which called for 64,000 bits per second, led to this system being superseded by B8ZS ...
UNIVAC 1105
... The UNIVAC 1105 had either 8,192 or 12,288 words of 36 bit magnetic core memory, in two or three banks of 4,096 words each ... Fixed-point numbers had a one-bit sign and a 35-bit value, with negative values represented in ones' complement format ... Floating-point numbers had a one-bit sign, an eight-bit characteristic, and a 27-bit mantissa ...
... Since version 11 of Adobe Flash Player, released October 4, 2011, 64-bit and 32-bit builds for Windows, Mac and Linux have been released in sync ... Previously, Adobe offered experimental 64-bit builds of Flash Player for Linux, from November 11, 2008 to June 15, 2010 ...
Manchester Code - Description
... Extracting the original data from the received encoded bit (from Manchester as per 802.3) original data XOR clock = Manchester value 0 ... Summary Each bit is ... code always has a transition at the middle of each bit period and may (depending on the information to be transmitted) have a transition at the start of the period also ... The direction of the mid-bit transition indicates the data ...

### Famous quotes containing the word bit:

unless I can shake myself free of my dog, my flag,
of my desk, my mind, I find life a bit of a drag.
Not always, mind you. Usually I’m like my frying pan
useful, graceful, sturdy and with no caper, no plan.
Anne Sexton (1928–1974)

The women of my mother’s generation had, in the main, only one decision to make about their lives: who they would marry. From that, so much else followed: where they would live, in what sort of conditions, whether they would be happy or sad or, so often, a bit of both. There were roles and there were rules.
Anna Quindlen (20th century)

The average Kentuckian may appear a bit confused in his knowledge of history, but he is firmly certain about current politics. Kentucky cannot claim first place in political importance, but it tops the list in its keen enjoyment of politics for its own sake. It takes the average Kentuckian only a matter of moments to dispose of the weather and personal helath, but he never tires of a political discussion.
—For the State of Kentucky, U.S. public relief program (1935-1943)