Apple Logic Pro 9 - Manual (Page 90)

The Preferences and Project Settings windows are examples of floating windows.
Floating windows are usually recognizable by their narrower, gray title bar (except the
plug-in window, which has a different title bar style). Mouse operations performed in
floating windows behave in the same way as in normal windows.
Handling Background Windows
Background windows are not fully obscured, and can be identified by a dimmed title bar
and a faded name. They can be positioned next to the top window, or tiled underneath
it.
In background windows, you cannot only observe changes, but make almost any kind
of change, without needing to give the window key focus before making alterations.
Independent tool selection is memorized for each window, allowing you to directly edit
the contents of any window, whether it has key focus or not. As soon as any such edits
are made, the window is automatically made the key focus window. For example, suppose
you have an Arrange window with the Piano Roll Editor and Event List visible: the Pointer
tool is active in the Arrange area, the Pencil tool is active in the Piano Roll Editor, and the
Eraser tool is active in the Event List. The tool automatically becomes active as you drag
the mouse pointer across the boundaries of each window.
Opening and Closing Windows
There are various ways to open and close windows in Logic Pro.
90 Chapter 4 Customizing Your Window Setup