zettabytes

A zettabyte (symbol ZB) is a unit of digital information equal to 10^21 bytes. It is part of the SI prefixes used to quantify data storage, with zetta- representing 10^21. In practical terms, a zettabyte is about one trillion gigabytes or one billion terabytes. The term is used for describing very large data volumes such as total global data storage or annual data generation.

Decimal versus binary prefixes can cause confusion. The zetta- prefix is a decimal SI prefix. In computing, binary prefixes are sometimes used, such as the zebibyte (ZiB), which equals 2^70 bytes, or about 1.1806 × 10^21 bytes—roughly 18% larger than a zettabyte.

Context and usage. Zettabytes appear in discussions of large-scale data infrastructure, including global data center capacity, cloud storage, and internet traffic. Analysts may report figures in zettabytes or in lower units such as exabytes when discussing more granular measurements.

History and adoption. The zetta- prefix was introduced as part of the SI system to name increasingly large data quantities, and zettabyte usage has grown with the expansion of digital information, cloud services, and the scale of data collected and processed worldwide. While practical measurements often use exabytes for finer granularity, zettabytes are employed to convey orders of magnitude in large-scale data discussions.