The K Desktop Environment

1.3. Window Focus policy.

The window that is "in focus" receives keyboard input and has the active titlebar appearance (usually colored instead of gray). The focus can be switched to another window with the keyboard (Alt+Tab) or the mouse. The Focus policy determines which window is in focus at a given time. When the focus policy follows the KDE style, the Alt+Tab key combination allows the focus to be transferred between windows on a graphical listing of the open windows.

Selection of the Auto Raise feature serves to raise a window to the front (top) when it gets the focus. If a delay in milliseconds is set using the slider control, the window is only raised if the mouse is still inside the window after a period equal to this delay has elapsed since focus passed to it. (This does not apply when the "click to focus" policy is in force).

Selection of the Click Raise feature allows a window to be raised to the front by clicking the mouse anywhere inside it. If this feature is not selected, only a click on a window's titlebar will raise it to the front. (This does not apply when the "click to focus" policy is in force).