Dongle

According to the strict definition of the term, a "dongle" is a small hardware device, which when connected to a computer helps authenticate a piece of software or the indentity of a user. In the absence of the dongle, the software may not run or may run in a restricted mode. Many software vendors use dongles, as it is generally perceived that it is difficult to copy a dongle than the software, thereby ensuring greater copy prevention or Digital Rights Management (DRM).

Off late the term "dongle" has acquired a different meaning and is used to describe specialized connectors that convert one type of port to another, for example USB flash drives or wireless networking adapters. Currently, the term "dongle" mostly refers to USB-based Bluetooth dongle, a device that connects into a computer’s USB port and enables the computer to communicate with other Bluetooth-enabled devices. As most personal computers do come with multiple USB ports, the USB Bluetooth dongle is the most widely preferred external Bluetooth adapter. A single Bluetooth dongle can be used to communicate with multiple Bluetooth devices.