Floating Mode refers to the placement of the toolbars on the canvas. If Floating Mode is selected, the toolbars will become a movable pop-up window instead of the default Fixed Mode on the left-side of the canvas.
The toolbars will have to be turned off then back on again before the change to Floating Mode will take effect.
The only way to turn off the Floating Mode is to select Fixed Mode.
How to use floating mode