The panel in the left column of the library window displays all the Groups and Group Sets in your library. The Groups called All References, Unfiled, and Trash are built into your library and cannot be changed. Additionally, if you use the Find Full Text feature, EndNote will automatically create a Group Set with 3 Groups titled Found PDF, Found URL, and Not Found. Any time you use Find Full Text for a citation, EndNote will automatically add the citation to one of those 3 Groups.
Note that when you add a citation to a Group, EndNote makes a copy of that citation that is linked with the "root" citation in your library. Removing a citation from a Group will not delete the citation from your library.
Groups are subsets, or folders, used to categorize and organize references. You can also share groups with collaborate with EndNote. Groups can be organized into Group Sets.
To create a Group or Group Set, select Groups from the menu bar. Select Create Group or Create Group Set.
When you create a Smart Group, EndNote will automatically add citations into the group if they fit the parameters you have specified.