A Dongle is a small USB device that you can use instead of a software license key, that you would normally have to key into your computer before gaining full access to a piece of software. With a Dongle on hand you will be able to install easyGUI on as many machines as you like, then move your Dongle around as you need it. So you can use our software on as many computers as you like, but only on one computer at a time. The Dongle has all the necessary software license data embedded in it, and this information is automatically detected by easyGUI each time the software is initialized. You are only allowed to have one Dongle per license that you own, as a Dongle is not an extra license.