A Layout Tab refers to a group of tool windows, which may be floating, tabbed with one another, or docked into a specific screen position. Layout Tabs may contain many items at a time - like several Charts, more than one WatchList, News and Notes, a User Group window, etc

Any time that you open any window, it opens as an undocked window. It floats within the context of the layout, but it's bound to the main layout. Floating a window will make the new window independent of the original program layout allowing you to move windows to multiple monitors.