Tweak mode lets you quickly move components under the mouse cursor regardless of whether you are currently using the Select Tool, Move Tool, Rotate Tool or Scale Tool. It’s useful for positioning objects in a scene or making quick adjustments to a specific mesh without switching to the Move Tool and selecting individual components each time.
You can activate tweak mode by holding ‘ on the keyboard and simultaneously dragging 
over the component you want to move. Alternatively, you can double-click the Move Tool in the toolbox and select Tweak mode.
Tweak mode is compatible with all component types. All manipulators disappear when tweak mode is active.
The Soft Selection settings apply to all of the transformation tools simultaneously. For example, if you turn on Soft Selection for the Move Tool, it stays on even if you select the Rotate Tool and maintains all of its settings.