Creating a cloud database?

As cloud computing seems to be one of the most popular topics, It got me thinking, And as i dont know much about the topic excuse me for any ignorance in the question.

What exactly is a cloud database and how would this service even be created. Would it simply be a MySQL database with a web frontend that would allow users to create their own databases/forms/report/relationships from their browser. Again, excuse my ignorance on the matter.

Whilst browsing i came across this InfoDome Product and it says that this is an online database. What exactly is the difference between this and a cloud database? also, if you look here at the video demo (http://vimeo.com/9132578) of the product it allows the user to create database forms and reports by using a drag and drop interface, How did they go about programming this feature because i found it very impressive.

Thanks for any help in clearing up my confusion.