# Binary number

A **binary number** is a number expressed in the **base-2 numeral system** or **binary numeral system**, a method of mathematical expression which uses only two symbols: typically "0" (zero) and "1" (one).

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The base-2 numeral system is a positional notation with a radix of 2. Each digit is referred to as a bit, or binary digit. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used by almost all modern computers and computer-based devices, as a preferred system of use, over various other human techniques of communication, because of the simplicity of the language and the noise immunity in physical implementation.[1]