The Inspector Bar comes in two editions. The first bar shown here, is visible if you have selected a shape, the second version is visible if you are editing text.
Below the Inspector Bar are the canvas rulers.
Using the View | Rulers you can turn on and off the visibility of the inspector bar and the rulers. You can also use the ⌘+R keyboard shortcut command. We'll deal with the ruler later on.
The really nifty thing about the Shape Inspector Bar is that it gives you quick access to geometry settings from the Geometry property inspector, color fillings from the Fill property inspector, line controls from the Line and Shapes property inspector, shadow control from the Shadow property inspector, and finally the connection toggle from the Connection property inspector.
Instead of opening and closing all these inspectors for a lot of common tasks, you can use the Shape Inspector Bar instead.
Granted, what you get from the Shape Inspector Bar...