Aura Possible purchase of Aura

I'm looking to possibly purchase the Aura (mainly because I'm currently using a 5"screen which fits nicely in my pocket) but I just have 1 major issue before I get it - I need to know how does it sort the books?

The one I currently have uses the drag and drop method and shows the folders and sub folders (and I have lots of these) like the documents folder on your computer, does the Aura do this or is it more like the Kindle where you have to organise the books by author/collection?

Thanks in advance.