BITS

In computer science a byte (pronounced "bite", IPA: /baɪt/) is a unit of measurement of information storage, most often consisting of eight bits. In many computer architectures it is a unit of memory addressing.

Prefixes for bit and byte
Decimal Value SI 10001 k kilo- 10002 M mega- 10003 G giga- 10004 T tera- 10005 P peta- 10006 E exa- 10007 Z zetta- 10008 Y yotta-	Binary Value IEC JEDEC 10241 Ki kibi- K kilo- 10242 Mi mebi- M mega- 10243 Gi gibi- G giga- 10244 Ti tebi- 10245 Pi pebi- 10246 Ei exbi- 10247 Zi zebi- 10248 Yi yobi-

Originally, a byte was a small group of bits of a size convenient for data such as a single character from a Western character set. Its size was generally determined by the number of possible characters in the supported character set and was chosen to be a divisor of the computer's word size; historically, bytes have ranged from five to twelve bits. The popularity of IBM's System/360 architecture starting in the 1960s and the explosion of microcomputers based on 8-bit microprocessors in the 1980s has made eight bits by far the most common size for a byte. The term octet is widely used as a more precise synonym where ambiguity is undesirable (for example, in protocol definitions).

There has been considerable confusion about the meanings of SI prefixes used with the word "byte", such as kilo- (k or K) and mega- (M), as shown in the chart Quantities of bytes. Since computer memory comes in powers of 2 rather than 10, the industry used binary estimates of the SI-prefixed quantities. Because of the confusion, a contract specifying a quantity of bytes must define what the prefixes mean in terms of the contract (i.e., the alternative binary equivalents or the actual decimal values, or a binary estimate based on the actual values).

A byte is one of the basic integral data types in some programming languages, especially system programming languages.

To make the meaning of the table absolutely clear: A kibibyte is made up of 1,024 bytes. A mebibyte is made up of 1,024 × 1,024 bytes. The figures in the column using 1,024 raised to powers of 1, 2, 3, 4 and so on are in units of bytes.

Prefixes for bit and byte
Decimal Value SI 10001 k kilo- 10002 M mega- 10003 G giga- 10004 T tera- 10005 P peta- 10006 E exa- 10007 Z zetta- 10008 Y yotta-	Binary Value IEC JEDEC 10241 Ki kibi- K kilo- 10242 Mi mebi- M mega- 10243 Gi gibi- G giga- 10244 Ti tebi- 10245 Pi pebi- 10246 Ei exbi- 10247 Zi zebi- 10248 Yi yobi-

In computer science a byte (pronounced "bite", IPA: /baɪt/) is a unit of measurement of information storage, most often consisting of eight bits. In many computer architectures it is a unit of memory addressing.

Originally, a byte was a small group of bits of a size convenient for data such as a single character from a Western character set. Its size was generally determined by the number of possible characters in the supported character set and was chosen to be a divisor of the computer's word size; historically, bytes have ranged from five to twelve bits. The popularity of IBM's System/360 architecture starting in the 1960s and the explosion of microcomputers based on 8-bit microprocessors in the 1980s has made eight bits by far the most common size for a byte. The term octet is widely used as a more precise synonym where ambiguity is undesirable (for example, in protocol definitions).

There has been considerable confusion about the meanings of SI prefixes used with the word "byte", such as kilo- (k or K) and mega- (M), as shown in the chart Quantities of bytes. Since computer memory comes in powers of 2 rather than 10, the industry used binary estimates of the SI-prefixed quantities. Because of the confusion, a contract specifying a quantity of bytes must define what the prefixes mean in terms of the contract (i.e., the alternative binary equivalents or the actual decimal values, or a binary estimate based on the actual values).

A byte is one of the basic integral data types in some programming languages, especially system programming languages.

To make the meaning of the table absolutely clear: A kibibyte is made up of 1,024 bytes. A mebibyte is made up of 1,024 × 1,024 bytes. The figures in the column using 1,024 raised to powers of 1, 2, 3, 4 and so on are in units of bytes.

Alternative words

Following "bit," "byte," and "nybble," there have been some analogical attempts to construct unambiguous terms for bit blocks of other sizes.^[4] All of these are strictly jargon, and not very common.

• 2 bits: crumb, quad, quarter, tayste, tydbit
• 4 bits: nibble, nybble
• 5 bits: nickel, nyckle
• 10 bits: deckle
• 16 bits: plate, playte, chomp, chawmp (on a 32-bit machine)
• 18 bits: chomp, chawmp (on a 36-bit machine)
• 32 bits: dinner, dynner, gawble (on a 32-bit machine)
• 48 bits: gobble, gawble (under circumstances that remain obscure)

Names for different units

The prefixes used for byte measurements are usually the same as the SI prefixes used for other measurements, but have slightly different values. The former are based on powers of 1,024 (2¹⁰), a convenient binary number, while the SI prefixes are based on powers of 1,000 (10³), a convenient decimal number. The table below illustrates these differences. See binary prefix for further discussion.

Prefix	Name	SI Meaning	Binary meaning	Size difference
k	kilo	103 = 10001	210 = 10241	2.40%
M	mega	106 = 10002	220 = 10242	4.86%
G	giga	109 = 10003	230 = 10243	7.37%
T	tera	1012 = 10004	240 = 10244	9.95%
P	peta	1015 = 10005	250 = 10245	12.59%
E	exa	1018 = 10006	260 = 10246	15.29%
Z	zega	1021 = 10007	270 = 10247	18.67%

Sometime "K" is used intead of "k". The use of "K" has as a prefix no meanings for the SI.