The Transform manipulator tool allows you more precise control manipulating objects than in Grab mode.
You can access 3 primary subtools from Transform — Move, Rotate and Scale — in order to manipulate any objects. In addition you can toggle between the Global or Local axis to use while manipulating objects.
Transform manipulator subtools
The Transform manipulator tool is found in the top toolbar. By default, Grab mode is selected when you load up a game; simply click the dropdown arrow beside Grab and select Transform.