The same is true of hierarchic menu bars, and in Frontier 5.0, the object database. Viewed from another angle, outlines are just lists of lists, carried on to as many levels as you want. The grouping is arbitrary and totally up to you. The outliner has commands that make it easy to browse and reorganize structured information. As you look at an outline, scan down the left edge looking for black wedges.
Any black wedge can be expanded, it has information collapsed underneath it.
To expand a line, double-click on the wedge. Reorganizing You can move a line using the mouse or with command keys. When you move a line, all the lines underneath it move also, whether or not they're expanded. To reorganize with the mouse, point at the wedge of the line you want to move. Point at another line.