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)).
Read more about Bit: History, Representation, Information Capacity and Information Compression, Multiple Bits, Bit-based Computing, Other Information Units
Famous quotes containing the word bit:
“This dog and man at first were friends;
But when a pique began,
The dog, to gain some private ends,
Went mad and bit the man.”
—Oliver Goldsmith (1730?–1774)
“One has to completely humiliate oneself to be what the Beatles were, and that’s what I resent. I didn’t know, I didn’t foresee. It happened bit by bit, gradually, until this complete craziness is surrounding you, and you’re doing exactly what you don’t want to do with people you can’t stand—the people you hated when you were ten.”
—John Lennon (1940–1980)
“So far we have been going firmly ahead, feeling the firm ground of prejudice glide away beneath our feet which is always rather exhilarating, but what next? You will be waiting for the bit where we bog down, the bit where we take it all back, and sure enough that’s going to come but it will take time.”
—J.L. (John Langshaw)