The diagram is entered in a logical grid. All objects are snapped to the grid. You can use the commands of the View menu for displaying of hiding the points of the grid. The (x,y) coordinates of the mouse cursor are displayed in the status bar. This helps you locating errors detected by the compiler, or aligning objects in the diagram.
At any moment you can use the commands of the View menu for zooming in or out the edited diagram. You also can press the [+] and [-] keys of the numerical keypad for zooming the diagram in or out.