(1) Billion (10 to the 9th power). Abbreviated "G," it is a prefix for capacities and speeds (gigabits, gigabytes, gigahertz, etc.). Giga may refer to 1,000,000,000 or 1,073,741,824, the latter based on the binary system (see
NIST binary). See
GB,
gig,
binary values and
space/time.
(2) A prefix attached to common, non-computer words that means a very large size or quantity. For example, "gigabucks" means a lot of money. Both "giga" and "mega" are used in this manner, although giga means billion and mega means million. See
mega.