In most computer systems, a byte is a unit of data that is eight binary digits long. A byte is the unit most computers use to represent a character such as a letter, number, or typographic symbol. Each byte can hold a string of bits that need to be used in a larger unit for application purposes. For example, a stream of bits can constitute a visual image for a program that displays images, and a string of bits can constitute the machine code of a computer program. Bytes are the smallest operable units of storage in computer technology.

Other important information about bytes includes:

• A byte can represent the equivalent of a single character, such as the letter B, a comma, or a percentage sign, or it can represent a number from 0 to 255.
• In some computer systems, four bytes constitute a word, a unit that a computer processor can handle efficiently as it reads and processes each instruction.
• Language scripts can sometimes require two bytes to represent a character. These are called double-byte character sets.
• The term "byte" was coined by Werner Buchholz in 1956 when working on IBMs Stretch computer.
• A kilobyte (KB) is 1,024 bytes, not one thousand bytes as might be expected, because computers use binary (base two) math, instead of a decimal (base ten) system.

In summary, a byte is a unit of data that is eight binary digits long and is the unit most computers use to represent a character such as a letter, number, or typographic symbol. Each byte can hold a string of bits that need to be used in a larger unit for application purposes.