Note that exa now officially means 10^18 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. So

1 exabyte = 1 EB = 10^18 bytes

1 exbibyte = 1 EiB = (1024)^6 bytes

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

It is permissible to use "exabyte" to mean exbibyte on a temporary basis until industry standards have shifted to the new terms.