(1) When decimal notation is used, giga stands for 10 to the 9th power. For example, a gigavolt is 1,000,000,000 volts.
(2) When applied to computers, which use the binary notation system, giga represents 2 to the 30th power, which is 1,073,741,824, a little more than 1 billion. A gigabyte, therefore, is about 1.073 billion bytes.