The scene inspector is used to navigate all objects in a world and view and edit the properties of any object. The scene inspector will let you modify absolutely anything in your current world. This includes things that could break how you interact with the world, so use caution when changing things that you are not familiar with; especially things on the root slot. You can always quit and come back to reset everything though; you won't break anything permanently unless you save changes to the world, so feel free to experiment.