A bit is the smallest unit of information. Information in binary digital computing devices is stored and processed in the form of bits. One bit corresponds to either a 1 or a 0 in the binary number system, or designates one of two possible logical values or states, such as "true" or "false." The word "bit," a contraction of the words "binary digit," was introduced in 1946 by John Tukey, an American statistician and pioneering computer scientist.

A bit can be physically represented within a computer or other device as a voltage condition (e.g., high or low), or as the presence or absence of a pit in the aluminum film layer of a CD or CD-ROM, or as the state of magnetization of a tiny area of a magnetic disk or tape, or as any other distinct pair of physical states, whether electronic, chemical, mechanical, or other. Inside an electronic...