the stage or period of greatest vigor, strength, success, etc.; prime: the heyday of the vaudeville stars. 2. Archaic. high spirits. Origin of heyday1.
A USB flash drive, also variously known as a USB drive, USB stick, thumb drive, pen drive, jump drive, flash-drive or USB memory, is a data storage device that includes flash memory with an integrated USB interface. USB flash drives are typically removable and rewritable, and physically much smaller than an optical disc.
A dongle is a piece of hardware, now usually a USB device (in the past, they also connected to serial and LPT ports), that plugs into a computer to provide copy protection for a piece of software.