Collections, or folders, are an easy way to group and organize your research. They are located in the left hand panel of your Zotero library known as the Collections Pane. You can further organize within a collection by creating subcollections or sub-folders. For example, you can use name each collection with your Course Names (WRIT 101, PACBASIN 100, etc.) and your sub-collections with your assignment name (Paper 1, Impact of Climate Change on Farming in Thailand, etc.).
Create a Collection: in your library, right-click "My Library" and select "New Collection" in the dropdown menu or click on the Collection icon (manila folder) and enter a collection name in the popup box.
Create a Subcollection: right-click any collection in the Collection Panel, and select "New Subcollection," and enter a name.
Delete a Collection: right-click a collection or subcollection in the Collection Pane and select "Delete collection" in the dropdown menu. This will delete the collection folder but keep your files in your overall Zotero library. Zotero will prompt you to confirm the deletion as a precaution and you can recover these from the Trash collection in case of a mistake.
Your Zotero library can be customized using columns similar to in a spreadsheet. You are able to add or remove columns other than the default columns of Title, Creator, Item Type, and Attachments.
You can tag (similar to hashtags on social media) the resources you add into your Zotero library to connect sources across collections. As you add tags to sources, you will be building your Tags Library located in the bottom left corner of the "My Library" page. Clicking on any tag in the Tags Library will bring up all of the sources you have with that same tag regardless of which collection they are located it. It's a good way to find similar sources. Please note that some sources can already have tags assigned to them by outside sources. They will have an orange tag icon while the tags you create will have a blue tag icon.
Using source metadata, Zotero will automatically track files it believes are duplicates and store them in a pre-existing Collection called "Duplicate Items" in the Collections Pane.
Click on a source title to compare the source description (metadata) information. You will need to select each version to see what, if any, differences there are in the metadata.
To merge duplicates: select the source to be the master (it will be greyed out) and click the "Merge 2 Items" button
To delete one: return to your library (search if applicable), right-click the source and choose "Move to trash" from the dropdown menu
To keep both: no action needed, but recommend adding a note to explain why you have different versions