Bit
- This article is about a unit of information, see Bit (disambiguation) for other meanings.
A
bit is an
information unit used in
computing and
information theory. It is the smallest unit of storage currently used in these fields, although much research is going on in
quantum computing with qubits. A single bit (short for
binary digit) is a 0 or a 1, or a true or a false, \nor for that matter any two mutually exclusive
states. A
byte is a collection of bits, originally variable in size but now usually eight bits. Eight-bit bytes are also known as octets. There are also terms for multiple bits using the standard range of prefixes, eg.
kilobit (kb),
megabit (Mb) and
gigabit (Gb).
bit ≪
Kilobit ≪
Megabit
By extension, ones or zeros in a computerised binary number (or a
byte) are called bits.
Telecommunications or
computer network traffic volume is usually described in terms of
bits per second. For example, a "56 k
bps modem" is capable of transferring data at 56 kilo
bits, k
b, in a single second (which is equal to 7 kilo
bytes, 7 k
B, with capitalised B to mark that we are talking about bytes and not about bits; in case of doubt, b is considered to mean
bit);
Ethernet transfers data at speeds ranging from 10 mega
bits per second to 1000 mega
bits per second (from 1.25 to 125 mega
bytes per second). The
SI prefixes
kilo-,
mega-, etc., are sometimes modified in meaning when applied to bits and bytes: for an explanation, see
Binary prefixes.
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See also
\n*Integral data type\n*
Bitstream\n*
Information entropy\n*
Qubit
Category:Computer terminology\nCategory:Units of information
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