When you work with the Morph tool, you will typically place a standard shape, then graphically edit it into its final form.
You can edit the Morph graphically using one of its sub-elements (face or edge). When you drag a face or edge, all of its connecting faces and edges move along with it.
The best way to learn this is to simply try out the editing options from the pet palette, using the 3D window. Don’t forget that, in many situations of Morph editing, you can reset the editing plane to any position.