What does gigabyte mean?
A gigabyte is a unit of digital information used to describe the size of computer memory, storage devices, files, and data transfers. In the decimal system, one gigabyte equals 10^9 bytes, or one billion bytes. In contexts based on binary multiples, however, it traditionally equals 2^30 bytes, or 1,073,741,824 bytes. The abbreviation GB is widely used on storage devices, internet plans, and digital file listings, while larger units include the terabyte and petabyte. Although the word is closely associated with computers, it also appears in general reporting about digital data, photographs, audio, video, and telecommunications. Its practical meaning can vary slightly according to convention: a device advertised as having one billion bytes of capacity may display a somewhat smaller figure when software reports its usable size using binary units. The term is formal, precise, and internationally understood, making it preferable to informal expressions when describing quantities of digital information.
nounA unit of digital information equal to 10^9 bytes, or one billion bytes, in the decimal convention. In computing contexts using binary multiples, it may instead equal 2^30 bytes.
- A unit of digital information equal to 10^9 bytes, or one billion bytes, in the decimal convention.
- A unit of digital information equal to 2^30 bytes, or 1,073,741,824 bytes, when a binary convention is used.
"The high-resolution photographs occupy several gigabytes of storage."
"The database backup file is nearly one gigabyte in size."
"This laptop includes 16 gigabytes of memory and a two-terabyte hard drive."
The regular plural is gigabytes; the abbreviation GB normally remains unchanged.
"The archive contains thousands of gigabytes of audio recordings."
A 'gigabyte' is a billion bytes in theory, but a familiar 2^30 bytes in many computer systems—the neat mathematical distinction hiding behind a simple abbreviation.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does gigabyte come from?
Gigabyte combines giga-, a prefix denoting a factor of one billion and derived from the Greek gigas, meaning “giant,” with byte, the standard unit of digital information. The giga- element was adopted in technical and scientific notation and later became common in computing as a way of naming units at the billion scale.
Related word forms
How gigabyte is actually used
The term is standard in computing, telecommunications, and media production, and its abbreviation is usually written as GB. Comparisons between advertised storage capacities and figures displayed by operating systems may appear inconsistent because the former commonly uses decimal units while the latter may use binary units.
Easily confused with gigabyte
A gigabyte measures eight times as much data as a gigabit because one byte contains eight bits.