A kilobyte (KB) is a multiple unit used for binary data. Although "kilo" generally refers to 1,000, in computer science, one kilobyte often refers to 1,024 (2^10) bytes.
The kilobyte is applied in a variety of measurement contexts, including:
RAM or ROM Memory size
Processor cache size
The amount of storage available on media such as an SD memory chip or flash drive
Hard disk drive storage capacity
An iPhone memory chip capacity