Byte, a unit of information built from bits, the smallest units of information used in computers. Bits have one of two absolute values, either 0 or 1. These bit values physically correspond to whether transistors and other electronic circuitry in a computer are on or off. A byte is usually composed of 8 bits, although bytes composed of 16 bits are also used. See Number Systems.

The particular sequence of bits in the byte encodes a unit of information such as a keyboard character. One byte typically represents a single character such as a number, letter, or symbol. Most computers operate by manipulating groups of 2, 4, or 8 bytes called words.

Software designers use computers and software to combine bytes in complex ways and create meaningful data in the form of text files or binary files (files that contain data to be processed and interpreted by a computer). Bits and bytes are the basis for creating all meaningful information and programs on computers. For example, bits form bytes, which represent characters and can be combined to form words, sentences, paragraphs, and ultimately entire documents.

Bytes are the key unit for measuring quantity of data. Data quantity is commonly measured in kilobytes (1024 bytes), megabytes (1,048,576 bytes), or gigabytes (about 1 billion bytes). A regular, floppy disk normally holds 1.44 megabytes of data, which equates to approximately 1,400,000 keyboard characters, among other types of data. At this storage capacity, a single disk can hold a document approximately 700 pages long, with 2000 characters per page.

The term byte was first used in 1956 by Germanborn American computer scientist Werner Buchholz to prevent confusion with the word bit. He described a byte as a group of bits used to encode a character. The eight-bit byte was created that year and was soon adopted by the computer industry as a standard.

The number of bits used by a computer’s Central Processing Unit (CPU) for addressing information represents one measure of a computer’s speed and power. Computers today often use 16, 32, or 64 bits in groups of 2, 4, and 8 bytes in their addressing.