How many bytes are in a gigabyte?

A gigabyte is defined as 1 billion bytes. This measurement is based on the binary system commonly used in computing, where a gigabyte is equal to 2^30 bytes (1,073,741,824 bytes), but is often simplified in common usage to represent it as 1 billion bytes for easier understanding.

In this context, the other options do not accurately represent the size of a gigabyte. For example, 1 million bytes corresponds to a megabyte, while 1 thousand bytes is equivalent to a byte, which is far less than a gigabyte. The figure of 10 billion bytes exceeds the standard definition of a gigabyte; therefore, 1 billion bytes is the correct and widely accepted answer for the size of a gigabyte in most discussions about data storage.