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: