Which prefix indicates a factor of 10^9?

The prefix that denotes a factor of 10^9 is "Giga." This prefix is commonly used in measurements to indicate a billion units of something, such as gigahertz (GHz) for frequency or gigabytes (GB) for data storage. Giga originates from the Greek word "gigas," meaning giant, which aptly reflects the large scale of this magnitude.

Other prefixes like Mega, Kilo, and Tera represent different powers of ten. Mega signifies a factor of 10^6 (one million), Kilo represents 10^3 (one thousand), and Tera indicates 10^12 (one trillion). Understanding these prefixes helps in various fields, especially in electrical and computer engineering, where such scales are often used for quantifying data, power, and frequency.