Kilobyte

A 51⁄4-inch floppy.

A kilobyte is a unit of information storage whose symbol is the kB (with the 'k' in lower case) and equals 10³ (thousand) bytes. Although the Greek prefix kilo- (χίλιοι) means "thousand", the term "kilobyte" and the symbol "kB" have historically been used to refer to both 1024 (2¹⁰) bytes to 1000 (10³) bytes, depending on the context, in the fields of computing and information technology. To solve this confusion, the International Electrotechnical Commission published in 1998 an appendix to the standard IEC 60027-2 where the binary prefixes were established, giving birth to the kibibyte unit to designate 2¹⁰ bytes. and considering the use of the word kilobyte invalid for said purposes.

The International System of Units and the term byte

In the early days of computing, units were displayed as multiples of 1000, but in the 1960s 1000 began to be confused with 1024, since computer memory works on a binary basis and not decimal. The problem lay in naming these units, since the names of the prefixes of the International System of Units were adopted. Given the similarity in the quantities, the base thousand prefixes that apply to the units of the international system (such as the meter, the gram, the volt or the ampere) were used.

However, it is etymologically incorrect to use these (decimal-based) prefixes to name binary-based multiples. As in the case of the kilobyte, despite the fact that 1024 is close to 1000.

This fact sowed certain confusions that, to this day, continue to be debated in the computer community.

To clarify the distinction between decimal and binary prefixes, the International Electrotechnical Commission (IEC), a standardization group, proposed in 1998 other prefixes, which consisted of abbreviated unions of the International System of Units with the word binary .

So, a set of 2¹⁰ bytes - or what is the same, 1024 bytes - should be called a kibibyte (KiB) contraction of "Binary Kilobyte".

This convention, expressed in the IEC 60027-2 and IEC 80000-13:2008 standards, has been adopted for the "Snow Leopard" from Apple and by Ubuntu. Others, such as Microsoft, adopt the definition found in dictionaries such as the Oxford (See references below), by maintaining the use of "kilobyte" for 1024 bytes.

In the computing environment, it has been suggested to use the uppercase K prefix to distinguish binary from decimal quantity, but this issue has not yet been standardized, since the symbol "K" in SI it represents the unit of temperature, the kelvin. On the other hand, this suggestion could not be extended to other prefixes of greater magnitude given that, in the example case of MB (megabyte), the SI already uses both the capital M (mega: million) and the lowercase (milli: thousandth).

Equivalence