Zettabit
The zettabit is a multiple of the unit bit for digital information or computer storage. The prefix zetta is defined in the International System of Units as a multiplier of 1021, and therefore
The zettabit has the unit symbol Zbit or Zb.
The zettabit is closely related to the zebibit, a unit multiple derived from the binary prefix zebi of the same order of magnitude, which is equal to =, or approximately 18% larger than the zettabit.