Definition: A kilobyte (KB) is a unit of data storage equal to 1,000 bytes. It's a multiple of the byte, which is the fundamental unit of information in computing.

History/origin: The kilobyte is based on the byte, which is derived from the bit, and is a unit that makes use of SI (International System of Units) prefixes. The term byte was coined in 1956 by Werner Buchholz. In 1998, the International Electrotechnical Commission defined new prefixes for the byte to be used in addition to their SI (International System of Units) counterparts, with the intent that the SI prefixes would be used when referencing 1000 bytes. The new prefixes would be used when referencing multiples of 1024 bytes (210), which is the binary definition of bytes used in information technology.

Current use: Kilobytes are commonly used for smaller files like text documents. Bytes are widely used when referencing data storage, particularly storage media such as hard drives, flash-based storage, and DVDs, though these are more often presented in terms of larger multiples of bytes such as megabytes or gigabytes.