1. A dongle is a cord connecting PC Cards or USB to external connections to network cables (RJ-45) and phone lines (RJ-11). The picture shows a PC Card dongle, a cable that connects to the end of the network card and allows for a standard RJ-45 network cable to connect to the other end.
2. With copy protection and software programs, a dongle is a hardware device that attaches to a computer that contains a unique electronic number. These devices are used with high-end programs to help verify the program has been legitimately purchased. Because these devices are difficult to recreate, it makes pirating these programs or using the programs on more than one computer almost impossible.
3. A dongle is a device allows the computer to be locked using either hardware or software to prevent unauthorized use.