Kilobyte

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); therefore one kilobyte is 1000 bytes. The unit symbol for the kilobyte is kB. In information technology, particularly in reference to main memory capacity, kilobyte is traditionally used to denote 1024 (2¹⁰) bytes. This arises from the powers-of-two sizing common to such memory in digital circuitry. In this context, the symbols K and KB are often used when 1024 bytes is meant.

In the International System of Units (SI) the prefix kilo means 1000 (10³); therefore one kilobyte is 1000 bytes. The unit symbol is kB.

This is the definition recommended by the International Electrotechnical Commission (IEC). This definition, and related definitions of prefixes mega- = 1000000, giga- = 1000000000, etc., are used for data transfer rates in computer networks, internal bus, hard drive and flash media transfer speeds, and for the capacities of most storage media, particularly hard drives,flash-based storage, and DVDs. It is also consistent with the other uses of the SI prefixes in computing, such as CPU clock speeds or measures of performance.

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