To move a freely floating (disconnected) object around your workspace, click on it and drag it to a new location using your mouse.
To move the object in much smaller increments, click on the object and use your keyboard arrows to move it up, down, left or right.
Moving Shapes in Automatic Diagrams
When a shape is connected to an intelligent formatting structure like in an org chart, grabbing it and moving it will automatically disconnect it from the structure. You can reattach the shape in a new location by dragging it over until the structure grabs it again in the new spot.
Moving Shapes Connected to Lines
When a shape is connected to other shapes via lines, when you move the shape, the lines will move with it.
You can disconnect the shape from the line by holding down the Alt key as you move it.
Related topics:
Move a Shape of Groups of Shapes