A bit (binary digit) is the base unit of information and is the smallest unit in which there is sufficient discrimination to communication any information.

Overview

A bit is a universal unit consisting of just two states - e.g., 1 and 0, true and false, on and off, up and down, heads and tails, punched or not punched or any other system that can represent two states. The correlation between these values and the physical states of the underlying implementation is a matter of convention. For example, digital electronics represent bits in transistors using a high voltage to represent a 1 and a zero voltage to represent a 0. Fundamentally, any form of information (e.g., text, sounds, pictures) can be represented in bits and be communicated over any system capable of being in just two states. A linear sequence of bits is called a binary string and the length of such sequence is known as a bit length.

Storage

A bit may be stored using any system capable of representing two states. A number of standards were introduced to describe the bit capacity of the medium.

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Transmission

Transmission of bits can be done using two methods:

• Serial communication - transfer of information, sequentially, one bit at a time.
• Parallel communication - transfer of information, sequentially, using multiple bits simultaneously.

The rate at which bits are transmitted is known as bit rate, measured in bits per second (bit/s or bps).

Bibliography

• Shannon, Claude Elwood. "A mathematical theory of communication."