yottabyte

The biggest type of byte I can possibly think of. One yottabyte can hold 1024^8 == 1,208,925,819,614,629,174,706,176 bytes of data! That's approximately 57,646,075,230,342,349 20-gig hard drives, people!

Note that yotta now officially means 10^24 even in the context of data processing. The prefixes kilo, mega, giga, tera, peta, exa, zetta, yotta always refer to powers of 10.

To refer to powers of 2^10 (powers of 1024), use the new binary prefixes kibi, mebi, gibi, tebi, pebi, and exbi. That is as high as they go; there are no official prefixes "zebi" or "yobi".

These new prefixes were created in December 1998 by the International Electrotechnical Commission: see the node prefixes for binary multiples for fuller explanation.