dongle

A dongle is a small piece of computer hardware that connects to a port on another device to provide it with additional functionality, or enable a pass-through to such a device that adds functionality.In computing, the term was initially synonymous with software protection dongles—a form of hardware digital rights management where a piece of software will only operate if a specified dongle—which typically contains a license key or some other cryptographic protection mechanism—is plugged into the computer while it is running.
The term has since been applied to other forms of devices with a similar form factor, such as adapters that convert ports to handle different types of connectors (such as DVI to VGA for displays, USB to serial connection, and in modern computing, USB-C to other types of ports, and Mobile High-Definition Link), USB wireless adapters for standards such as Bluetooth and Wi-Fi (the term "stick" or "key" is more commonly used to describe USB flash drives, as well as modern forms of dongles with slimmer form factors more akin to flash drives), and small form-factor digital media players that plug into HDMI ports.

View More On Wikipedia.org