Bit

This article is about the unit of information, see Bit (disambiguation) for other meanings.

A bit (abbreviated b) is the most basic information unit used in computing and information theory. A single bit (short for binary digit) is a zero or a one, or a true or a false, or for that matter any two mutually exclusive states.

A byte is a collection of bits, originally variable in size but now almost always eight bits. Eight-bit bytes are also known as octets. A four-bit quantity is known as a nibble. In some architectures, 16 bits make up a word, 32 bits a double word (dword): see word size.

Terms for large quantities of bits can be formed using the standard range of prefixes, e.g., kilobit (kbit), megabit (Mbit) and gigabit (Gbit). Note that much confusion exists regarding these units and their abbreviations, see Binary prefixes. Although it is clearer symbology to use "bit" for the bit and "b" for the byte, "b" is often used for bit and "B" for byte. (In SI, B stands for the bel.)

Telecommunications or computer network transfer rates are usually described in terms of bits per second.

The bit is the smallest unit of storage currently used in computing, although much research is ongoing in quantum computing with qubits.

Bit

See also