Kilobyte
The
kilobyte is a multiple of the unit byte for digital information. Although the SI prefix
kilo- means 1000, the term
kilobyte and symbol
KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information technology. For example, when referring to data transfer rates and to disk storage space, "kilobyte" means 1000 bytes. On the other hand, random-access memory capacity such as CPU cache measurements are always stated in multiples of 1024 bytes, due to memory's binary addressing. In the International System of Quantities, the kilobyte is 1000 bytes, while the kibibyte is 1024 bytes. The binary representation of 1024 bytes typically uses the symbol
KB, using an upper-case K. Informally sometimes the
B is dropped, making
K generally understood as 1024 bytes; however, this usage is not standardized and may be found used arbitrarily. All existing recommendations prefer to use the uppercase letter
B for byte, because
b is used for the bit.