Zotero allows you to organize your records into folders and sub-folders called collections and subcollections. You can create as many collections and subcollections as you want. (For example, before you start downloading Zotero records for a research project, you may decide to create a collection for that project.)
To create a collection, click on the folder image with the green plus sign in the upper left corner of the Zotero app.
Enter the name of the collection and click on OK.
Your new collection will show up under My Library. By default, new records you import will be contained in whichever collection you currently have selected (highlighted), but you may also choose a new collection from the drop-down menu. Work quickly, however; once the data has been pulled from the webpage it will automatically be saved.
You can create collections within collections, as well. These collections are called sub-collections because they are collections subordinate to another collection. However, after a collection has been created, you can move it into or out of preexisting collections by clicking and dragging the folder.
While Zotero will automatically search your entire collection while you're using the Word Processor plugin, it's still helpful to keep your records organized in the Zotero app. Zotero gives you a number of other options for using your collections; you can access them by right-clicking on any collection's name in the list.
New Subcollection: Zotero gives you the ability to separate different categories within each collection. You can next as many subcollections as you like.
Rename Collection: You can also rename any collection/subcollection by double-clicking on its title.
Delete Collection: This will delete the collection but leave your items. (The items will float in "My Library" until you relocate them.)
Delete Collection and Items: This will get rid of both the collection and all the records within it. Be careful; while you can reclaim your records from the trash, you'll have to reorganize them after you do.
Export Collection: If you or a colleague use another citation management program, you can export your data to it using those file types.
Create Bibliography from Collection: This gives you the ability to create a stand-alone bibliography from the items within this collection. You can either save the list to a new file, or copy it onto your clipboard to paste into an existing file.
Generate Report from Collection: This will provide you with an HTML list of all the citation information from the items in this collection, including any attachments or tags.