The Modify tools allow you to move, copy, delete, transform, and otherwise change existing objects in your drawing.
The Select objects tool modifies a set of objects in the same manner. Objects can be selected by picking individual objects (selecting them with the cursor), or by dragging a rectangle over the objects. Once selected, the set can be moved, copied, deleted, resized by handles, dynamically rotated, mirrored, or transformed. The selection can also be grouped, so that the entire selection becomes a single object.
The Edit object tool is used to make complex changes to individual objects. The editing options available depend on the type of object selected.
The Edit group tool is used modify the definition of a group. The group is identified by selecting an instance (or copy) of the group in the active drawing drawing. Once a group is selected, individual members can be moved or deleted; additional objects can be added; the origin and insert alignment points can be moved; and properties of the group and individual members can be viewed or changed. If there is more than one instance (or copy) of the group, the changes can be made globally (affecting all copies) or only to the selected copy.