Default Mode

      Move all active objects forwardly.
      Move all active objects backwardly.
      Move all active objects to front.
      Move all active objects to back.

Using these tools when two or more objects selected results in the objects being aligned in reference to the edges of the bounding box. For example, when two objects are selected and align top is selected, the top side of the lower object in the workspace will be aligned to the top side of the object above it. When only one object is selected, that object will be aligned in reference to the edges of the animtaion.

Aligns the centers of the object selected in reference to the animation's edges.
In addtional,you can Select Object(s) or Drag Object(s) In Default Mode.