1bit

1bit, more commonly written as “one bit,” is the basic unit of information in computing and digital communications. It represents a binary decision between two distinct states, typically labeled 0 and 1. In information theory, a bit is the amount of information needed to resolve a single binary choice where the two outcomes are possible.

As a measure of information, one bit is the logarithm base 2 of two possibilities. If the two states are equally likely, the uncertainty or entropy is exactly 1 bit. If the probabilities are unbalanced, the average information per outcome is less than one bit.

In practical terms, computers organize data in bits. A single storage cell or line can hold one bit of information, and a group of eight bits forms a byte, which is a common building block for representing data. Most modern architectures treat a byte as the smallest addressable unit, though some historical or specialized systems used smaller or larger basic units.

The concept of the bit underpins digital communication, data encoding, error detection and correction, and information processing. It was popularized in the mid-20th century, with the term “bit” attributed to John W. Tukey in 1947 and later employed by Claude Shannon in information theory.

See also: byte, bit rate, binary numeral system, information theory.