The EndNote Library Window
with Three Panes

Groups Pane - displays all of the various groupings of references available. There are several types of groups, some permanent, some temporary. and some user created.
References Pane displays all of the references in a highlight group or the references just imported from a search.
Tabs Pane displays 1) A Preview of the highlighted reference in the Reference Pane; 2) Search criteria for searching from within EndNote, or 3) Quick Edit tab where you can quickly change or add information to the highlighted reference.