Left

Positions all objects in such a manner that all the encompassing rectangles of the selected objects align themselves left  of the first marked object.

Right

Positions all objects in such a manner that all the encompassing rectangles of the selected objects align themselves right of the first marked object.

Top

Positions all objects in such a manner that all the encompassing rectangles of the selected objects align themselves to the top of the first marked object.

Bottom

Positions all objects in such a manner that all the encompassing rectangles of the selected objects align themselves to the bottom of the first marked object.