Identify the prefix that represents 10^9.

The prefix that represents 10^9 is Giga. In the metric system, prefixes are used to denote different powers of ten. The prefix "Giga" specifically refers to one billion, or 10^9. This is commonly used in various fields, including computing, where gigabytes (GB) signify a billion bytes of data.

In contrast, the prefix "Mega" corresponds to 10^6, or one million; "Kilo" refers to 10^3, or one thousand; and "Hecto" represents 10^2, or one hundred. Understanding these prefixes is essential for accurately interpreting measurements and quantities in scientific and technical contexts.