Dongle is a generic term for a typically small device that attaches to your computer to provide some sort of functionality, sometimes specific to an application.
Examples of dongles include:
- Copy-protection devices that must be attached for an application to work
- Mobile broadband “modems”
- External network adapters, wired or wireless
- Flash drives
Most dongles are USB devices these days, but the term doesn’t actually imply a type of connector. Historically, communications ports, printer ports, and other types of external ports on a computer have all been used.