When your work does not involve using the tools in a toolbar, you can close it to tidy up the work area. For example, if you are not adding review comments to a PDF, there’s no need to have the Comment & Markup toolbar open.
When you need easy access to a toolbar that is hidden by default, you can open it. This toolbar appears as a floating palette, which you can move or dock in the toolbar area.
Locking the toolbars prevents any rearrangement of the toolbar area, so all grabber bars disappear when the toolbar area is locked. Locking does not affect the positions of any floating toolbars.
Select the command a second time to unlock the toolbar area.