OLE: User-Interface Overview
Implementing OLE functionality in your program affects your user interface in several ways:
Visual editing (in-place activation) displays the user interface of another program in your program's windows and modifies your program's menus with items from the other program.
Drag and drop allows users to drag objects within and between windows and even between programs.
Trackers provide visual cues to the state of objects during visual editing and drag and drop.