Creating groups allows you to break a large library into subsets according to various tasks you might be working on, or themes in your research. EndNote allows only two levels of hierarchy when it comes to groups: Groups and Group Sets. A group set allows for multiple groups to be clustered under a single heading.
To add a reference or references to a group, select them and then either drag them to the group or right-click on the selected references and choose Add References To.
Groups can be moved from one group set to another by click-dragging to a new location.
You can also delete a group or a group set by right-clicking and choosing Delete. Deleting groups and group sets will not result in references being lost from your EndNote Library.
EndNote adds new references to Smart Groups automatically, according to criteria that you choose.
To create a Smart Group: