Selecting this option toggles histogram title bars off and on. A check appears next to the option if title bars will be shown.
Disabling this option (turning off the display of titles) allows the histogram graphics to occupy more space on the screen. Moving and sizing the histograms becomes a two-step process, however.
To move or size a histogram without a title bar, click your left mouse button on one corner of the histogram window, hold the button down and drag that corner to its new location. Release the button. Click on the diagonally opposite corner, drag it and release to complete the moving-sizing operation.