A yottabyte is a unit of information or computer storage equal to one septillion (one long scale quadrillion or 1024) bytes. It is commonly abbreviated YB. At this time, no computer has one yottabyte of storage. Because of a traditional inconsistency, "yottabytes" are often intended to mean yobibytes in common speech. This usage is not recommended as it creates confusion (see below) and has been facing increasing opposition by many technical standards and legal entities in the past few years.
|Quantities of bytes|
Because of irregularities in the definition and usage of terms for byte multiples, the exact number can be either one of the following:
- or 1 septillion 1,000,000,000,000,000,000,000,000 bytes — 10008, or 1024.
- 1,208,925,819,614,629,174,706,176 bytes — 10248, or 280.
Because of these irregularities, the term "yobibyte" has been proposed as an unambiguous reference to the latter value.
Yottabyte can, in theory, store everything in the entire universe.