Zotero organizes your research into collections that act like iTunes playlists. Research items can be added to any number of named collections and subcollections, which in turn can be organized however you like. With saved searches, you can create smart collections that automatically fill with relevant materials as you add them to your library.
Assign tags to your library items to organize your research using your own keywords. The tag selector enables you to filter your library instantly to view matching items. Zotero can even use database and library data to tag items automatically as you add them.
Moving citations to different groups
Zotero "Sorting through your Zotero library" Vimeo. 2010. Web. 1 May 2014.