Ghosts are helper objects that show poses and positions (in form of silhouettes) that a character assumes on the previous and subsequent frames, so you can see how the current pose fits with the animation in its entirety. The tool for controlling ghosts can be found in the interface panel at the top of the main window.
Ghosts can be rendered in a number of different modes. You can adjust them in the list on the Toolbar:
Disables ghost rendering
Shows ghosts of the previous frames
Shows ghosts of the subsequent frames
Shows ghosts of both previous and subsequent frames
Shows ghost of the framesl selected on the timeline
Toggles Key Frame mode. If this button is enabled, every mode described above will only render the ghosts of key frames
Note: If the key frame mode is selected, a key symbol is shown near every icon on the list.
The number of previous and subsequent frames can be set in the fields at the left and right sides of the list. These fields are disabled if Key Mode Selection is set