Working with Toolboxes
Toolboxes are hierarchical; that is, there are "parent-child" relationships between toolboxes. The "parent" toolbox displays one tool from each of its "child" toolboxes.
You can select any tool that is a member of a "child" toolbox from that toolbox's "parent" without floating the "child" toolbox. This aspect of toolboxes helps you minimize the screen space they occupy.