A gibibyte (GiB) is a unit of measure of capacity used in computing. The prefix gibi originated with the binary system for measuring data capacity, which is based on powers of two. One gibibyte equals 230 or 1,073,741,824 bytes.
The binary prefixes include kibi, mebi, gibi, tebi, pebi, exbi, zebi and yobi. The International Electrotechnical Commission (IEC) created these prefixes in 1998. Prior to that, the metric prefixes in the International System of Units (SI) were used across the board to refer to both the decimal system's power-of-10 multipliers and the binary system's power-of-two multipliers. The prefixes used in the SI system include kilo, mega, giga, tera, peta, exa, zetta and yotta.
Before 1998, context determined which system a person was referring when they used the term gigabyte (GB). That term could refer to either 109 bytes (1,000,000,000 bytes) or 230 (1,073,741,824) bytes.
After 1998, who used which of the two systems depended on the discipline or industry a person was in. The communications, electronics and physics sectors are more likely to use the decimal system's metric units. The information technology and data storage industries tend to use the binary system and its non-metric units.
As the computing industry has matured, having the same prefixes refer to two different units of measure became confusing. Disk drive manufacturers tended to use the decimal system when labeling the capacity of hard disk drives (HDD) and solid-state drives (SSDs). Alternatively, operating system (OS) vendors often used the binary, power-of-two system to measure computer memory and data storage capacity. As a result, a disk drive manufacturer would label a new HDD as having 100 GB of capacity. However, when the customer installed that hard drive, the computer OS would report that the drive only had 93.13 GB capacity.
Discrepancies such as that led the IEC to create the new prefixes for the binary of measurement. If the OS had used the binary system prefixes in the example above, it would have reported 93.13 GiB instead of 93.13 GB.
The confusion around these terms continues today.
A gibibyte and a gigabyte are sometimes used as synonyms, though technically they do not describe the same amount of capacity. They are close in size, however.
In terms of a kibibyte vs. a kilobyte or a mebibyte vs. a megabyte, the difference between binary prefixes as units of measure and the decimal system is nearly negligible. But when you're talking gibibytes vs. gigabytes, that 7% difference can start to add up. At this higher level of capacity measurement, the difference between the two systems becomes magnified.
The article is partly borrowed from techtarget.
