Well, I really don't know what it's so hard to understand, they have a free version for some of the features and a demo version for the full version. It's just like AVG anti-virus, for example. You surely know that they have a free version which u can have it all the time and a full version which u must buy it. And at this full version there is a demo to test its features.
That's exactly the same case for
tunebite, the free version u have full access to its features all the time and with demo version u can just try the features from the full version which aren't the same as the free version.
