A dongle is a small hardware device which accompanies a program and which attaches to one of the computers ports, typically serial or USB. The program will not run unless the dongle is present. A dongle must never be installed or removed while the power is on or it will be damaged. Logic Audio and Lightwave both use dongle's.
Installation of the program will halt unless an owner serial number (supplied with the program) is entered. The serial number is retrievable from any media created with the software by the software's authors. Most DTP software is protected in this way.
During installation an authorisation floppy (supplied with the program) must be inserted. It contains 2 or 3 "invisible" authorisation files. If the installation program finds an unused file it will allow installation to continue. Programs installed in this way must be uninstalled to ensure no authorisation's are "lost".
Having installed the software from the installation CD, from time to time the software requests that the CD is used to "re-authorise" the software. Steps are taken to ensure that the CD cannot be cloned or its contents copied to another storage device.
Web challenge/response /serial number codes
During installation a number which identifies your computer is retrieved. Together with a serial number (normally supplied with the software license) this number must be entered into the publishers web site. Shortly after, a unique unlock code is emailed to you which allow you to complete installation.