The prefix "giga-" denotes a factor of one billion, or 10^9. It is commonly used in various fields, including computing and science, to describe large quantities. For example, a gigabyte (GB) is a unit of digital information storage equal to approximately one billion bytes. In the context of measurements, "giga-" can also refer to large-scale phenomena, such as giga-hertz (GHz), which measures frequency in billions of cycles per second. This prefix helps simplify communication about vast numbers, making it easier to understand and compare large data sizes or quantities in everyday life.