A
device that attaches to a computer to control access to a particular
application. Dongles provide the most effective means of
copy protection. Typically, the dongle attaches to a PC's
parallel port. On
Macintoshes, the dongle sometimes attaches to the
ADB port. The dongle passes through all data coming through the
port so it does not prevent the port from being used for other purposes. In fact, it's possible to attach several dongles to the same port.