Can someone please explain to a noob the difference between categories, folders and topics?
Topics and items are two types of elements (“pages of information”) in SuperMemo. Topics may be used to display longer general texts for reading. Items may be used to display specific questions and answer that test your memory. Only items ask for grades in learning. Folders are elements that keep together a bundle of other elements. They are like folders in Windows, only instead of keeping Windows folders and files, they keep topics and items (and other SuperMemo folders). Categories are like special super-folders that keep elements together and make sure they are provided with some special properties (e.g. color, font, picture, etc.