What is a USB flash drive?

A universal serial bus (USB) flash drive is a small, portable device that plugs into a computer's USB port. Like a hard disk, a USB flash drive stores information, but with a flash drive you can easily transfer that information from one computer to another. USB flash drives vary in size and shape and can hold gigabytes of information. USB flash drives are also called pen drives, key chain drives, key drives, and memory keys.