Bit

Short for BInary digiT. The smallest element of computer storage, it is a single digit in a binary number (0 or 1). The bit is physically a transistor or capacitor in a memory cell, a magnetic spot on disk or tape, or a high or low voltage pulsing through a circuit.

Groups of bits make up storage units in the computer, called characters, bytes, or words, which are manipulated as a group. The most common is the byte, made up of eight bits and equivalent to one alphanumeric character.