Zettabit

The zettabit is a multiple of the unit bit for digital information or computer storage. The prefix zetta (symbol Z) is defined in the International System of Units (SI) as a multiplier of 1021 (1 sextillion, short scale), 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.