The kilobyte is a multiple of the unit byte for digital information.
The International System of Units (SI) defines the prefix kilo as 1000 (103); per this definition, one kilobyte is 1000 bytes. The internationally recommended unit symbol for the kilobyte is kB.
In some areas of information technology, particularly in reference to solid-state memory capacity, kilobyte instead typically refers to 1024 (210) bytes. This arises from the prevalence of sizes that are powers of two in modern digital memory architectures.