USB flash drive
(n.) A small, portable flash memory card that plugs into a computer��s USB port and functions as a portable hard drive. USB flash drives are touted as being easy-to-use as they are small enough to be carried in a pocket and can plug into any computer with a USB drive. USB flash drives have less storage capacity than an external hard drive, but they are smaller and more durable because they do not contain any internal moving parts.
USB flash drives also are called thumb drives, jump drives, pen drives, key drives, tokens, or simply USB drives.