A GB, or Gigabyte, is a unit of digital information storage that is commonly used to measure data size. One gigabyte is equivalent to 1,024 megabytes (MB) or about one billion bytes. It is often used to describe the capacity of storage devices like hard drives, USB flash drives, and memory cards. In computing, a gigabyte can also refer to the amount of data that can be transferred or processed. For example, a typical smartphone might have storage capacities ranging from 32 GB to 512 GB, indicating how much data, such as apps, photos, and videos, it can hold.